Trends and Innovations in Energetic Sources, Functional Compounds and Biotechnology: Science, Simulation, Experiments 9783031465451, 3031465458

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Engineering Materials

Carlton A. Taft Paulo Fernando de Almeida   Editors

Trends and Innovations in Energetic Sources, Functional Compounds and Biotechnology Science, Simulation, Experiments

Engineering Materials

This series provides topical information on innovative, structural and functional materials and composites with applications in optical, electrical, mechanical, civil, aeronautical, medical, bio- and nano-engineering. The individual volumes are complete, comprehensive monographs covering the structure, properties, manufacturing process and applications of these materials. This multidisciplinary series is devoted to professionals, students and all those interested in the latest developments in the Materials Science field, that look for a carefully selected collection of high quality review articles on their respective field of expertise. Indexed at Compendex (2021) and Scopus (2022)

Carlton A. Taft · Paulo Fernando de Almeida Editors

Trends and Innovations in Energetic Sources, Functional Compounds and Biotechnology Science, Simulation, Experiments

Editors Carlton A. Taft Centro Brasileiro de Pesquisas Físicas Rio de Janeiro, Rio de Janeiro, Brazil

Paulo Fernando de Almeida Universidade Federal da Bahia Instituto de Ciencias da Saude Salvador, Bahia, Brazil

ISSN 1612-1317 ISSN 1868-1212 (electronic) Engineering Materials ISBN 978-3-031-46544-4 ISBN 978-3-031-46545-1 (eBook) https://doi.org/10.1007/978-3-031-46545-1 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Paper in this product is recyclable.

Preface

This book offers roadmaps to new trends and innovations that address challenges such as energy and environment. Topics related to bio and phyto technologies are also addressed. Chapter “SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties for NO Reduction with CO in the Presence of O2 ” describes experimental investigation of the usage of perovskites for reduction of nitric oxide in the environment. Chapter “Overview: Photovoltaic Solar Cells, Science, Materials, Artificial Intelligence, Nanotechnology and State of the Art” presents an overview of solar cells, including technologies, devices, actual status and future perspectives highlighting potential of hybrid quantum dot cells and trends to make new technologies available. Chapter “Techniques to Characterize the Photoactivity of Semiconductor Materials Defining Performance in Advanced Oxidation Processes and Fuel Generation” emphasizes consolidation/exploitation of solar applications as a sustainable way to mimic photosynthesis producing energy vectors (H2 ) and wastewater treatment via semiconducting materials. Chapter “Electronic Structure of the Fe-doped TiSe2 Material: What Quantum Conditions Improve the Efficiency in the Energy Transmission Technology?” presents scientific research of materials with superior conductive phenomena to decrease loss of energy during electrical transmission in wires, i.e., properties of superconductor lamellar materials. Chapter “Revisiting the Underlying Chemistry Enhancing the Activity of Photoelectro- and Photo-Catalysts Concerning H2 Production” describes techniques used to evaluate photoactivity of semiconductive phases for H2 production. Chapter “An Integrated Computational Modelling of the Wettability of Rock Formations in Rock-Brine-Oil Systems” presents scientific research to explain and discuss low salinity water injection, smart water technologies and design of injection fluids to increase the oil recovery factor. Chapter “Biohydrogen Production and Its Integration with Industrial and Urban Effluent Recycling” address cost-effectiveness, high energy density, low pollution levels and renewability of hydrogen obtained from biological production. Chapter “Biotechnological Strategies to Simultaneous Capture of CO2 and Conversion of H2 S into Valuable Bioproducts in Oil Reservoirs address desulfurization of effluents and natural gas as well as sequestration of CO2 for renewability and sustainabillity.

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Preface

Chapter “Propidium Monoazide Real-Time Quantitative Polymerase Chain Reaction for Sulfate Reducing Bacteria Viability Assay” discuss innovation, detection and quantification of environmental relevant sulfate reducing bacteria providing the oil industry with an overview of corrosion and other phenomena of economic importance. Chapter “Evaluation of Potential Anxiolytic Activity of TRPV1 Antagonists Using Pharmacophore-Based Virtual Screening” reports research focused on therapeutic innovations for treatment of anxiety disorders. Chapter “In Silico Studies for the Analysis of Psychedelic Substances with Potential Activity for the Treatment of Epilepsy” presents scientific research with the aim of shedding light on studies of hallucinogens as potential treatments for mental disorders. Chapter “Protein–Protein Interaction for Drug Discovery” underlines strategies for the development of inhibitors for the interactions between proteins based on their direct interaction with the binding interface of their partner proteins. Chapter “SARS-CoV-2 Spike Protein: A Review of Structure, Function, Care, Vaccines, and Possible Inhibitors Designed by Molecular Modeling” describes techniques such as structure- and ligand-based virtual screening, molecular docking, pharmacophoric modeling, quantitative structure-activity relationships, and artificial intelligence used for planning and repositioning of drugs capable of inhibiting the infection by COVID-19. Chapter “Electronic Structure Analysis of Dasatinib Inhibition of Focal Adhesion Kinase” reports research using density functional theoretical computational studies to analyze potential binding of dasatinib, a kinase drug inhibitor, with focal adhesion kinase (FAK) binding site. Chapter “Immunobiological Therapies in Rheumatoid Arthritis: Mechanisms of Action and Future Perspectives” address concepts of immunobiological therapies based on the use of antibodies for rheumatoid arthritis, as well as the basis of the immune response with a focus on relevant therapeutic targets and the molecular mechanisms for interference in the pathophysiology. Chapter “Drug-Like Properties of Copaiba Tree Oil-Resin Active Ingredients” discuss the anti-inflammatory, wound healing, antitumor, antiseptic, germicidal, antifungal, antibacterial, larvicidal and gastric protection activities of copaiba plant species with potential treatment for inflammatory, rheumatic and infectious diseases. Chapter “In Silico Approaches in Pesticides” describes computational tools that can help develop increasingly specific, less toxic pesticides in relation to environment and human beings. Chapter “Statistical Approaches Applied to Herbal Product Development” explains the usage of statistical methods to optimize production, protection of herbal medicinal products. Chapter “Advanced Applications of Lignocellulosic Fibers and Mycelium-Based Composites for a Sustainable World” discuss advantages of using biodegradable fibers that can be easily disposed of after usage (cleaning oil spills and other pollutants in water, for example) without harming the environment. Chapter “In Silico Design of Acetylcholinesterase and Glycogen Synthase Kinase-3β Multi-target Inhibitors” investigates selection of reference compounds derived from natural products and employs different computational

Preface

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methodologies to elucidate their possible affinity towards enzymes AChE and GSK3β enabling planning and development of promising proposals, able to perform dual inhibition of such targets, with interest in Alzheimer’s disease therapeutics. Chapter “Evaluation of the Effect of the Application of Electrical Current in Micromamperage During Alcoholic Fermentation by Saccharomyces Cerevisiae” presents research of ethanol (fermented and/or distilled) importance for the production of beverages or biofuels as well as methods including applications of electrical current that could optimize production of bioethanol. Chapter “Design of Cannabinoid-Based Drugs for the Treatment of Parkinson’s Disease” investigates, plans and develop numerous cannabinoid-derived drugs capable of treating Parkinson’s disease. Chapter “Exploring Innovative Exogenous Green Stimulus Methods for Boosting Bioprocesses: Electric, Magnetic and Ultrasound Stimulation Techniques” investigates non-invasive, non-toxic techniques shown to enhance metabolic activity and stress response of microbial systems (bacteria, yeasts, fungi, microalgae) leading to increased yields of valuable bioproducts and bioremediation technologies. Rio de Janeiro, Brazil Bahia, Brazil

Carlton A. Taft Paulo Fernando de Almeida

Contents

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties for NO Reduction with CO in the Presence of O2 . . . . . . . . . . . Marcelo Rodrigues, André Luiz Menezes de Oliveira, Elaine C. Paris, Elson Longo, Heloysa M. C. Andrade, and Iêda Maria Garcia dos Santos

1

Overview: Photovoltaic Solar Cells, Science, Materials, Artificial Intelligence, Nanotechnology and State of the Art . . . . . . . . . . . . . . . . . . . . Carlton Anthony Taft and Jose Gabriel Solano Canchaya

27

Techniques to Characterize the Photoactivity of Semiconductor Materials Defining Performance in Advanced Oxidation Processes and Fuel Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daniela Palomares-Reyna, Adriana N. Gutiérrez-Lopez, Fabiola S. Sosa-Rodríguez, and Jorge Vazquez-Arenas

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Electronic Structure of the Fe-doped TiSe2 Material: What Quantum Conditions Improve the Efficiency in the Energy Transmission Technology? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Guilherme Bonifácio Rosa, Gabriel G. da Rocha, Alcione Jurelo, and Sergio R. de Lazaro Revisiting the Underlying Chemistry Enhancing the Activity of Photoelectro- and Photo-Catalysts Concerning H2 Production . . . . . . . 119 Fabiola S. Sosa-Rodríguez, Luis A. Estudillo-Wong, Ricardo E. Palma-Goyes, and Jorge Vazquez-Arenas An Integrated Computational Modelling of the Wettability of Rock Formations in Rock-Brine-Oil Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 Elias Ramos-de-Souza, Elias Silva dos Santos, and Anaís Couto Vasconcelos

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Contents

Biohydrogen Production and Its Integration with Industrial and Urban Effluent Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Igor Carvalho Fontes Sampaio, Isabela Viana Lopes de Moura, Josilene Borges Torres Lima Matos, Carlton Anthony Taft, Cleveland Maximino Jones, and Paulo Fernando de Almeida Biotechnological Strategies to Simultaneous Capture of CO2 and Conversion of H2 S into Valuable Bioproducts in Oil Reservoirs . . . . 185 Paulo Fernando de Almeida, Igor Carvalho Fontes Sampaio, Fábio Alexandre Chinalia, Carlton Anthony Taft, Isabela Viana Lopes de Moura, and Cleveland Maximino Jones Propidium Monoazide Real-Time Quantitative Polymerase Chain Reaction for Sulfate Reducing Bacteria Viability Assay . . . . . . . . . . . . . . . 195 Igor Carvalho Fontes Sampaio, Josilene Borges Torres Lima Matos, Fabio Alexandre Chinalia, Andreas Stöcker, and Paulo Fernando de Almeida Evaluation of Potential Anxiolytic Activity of TRPV1 Antagonists Using Pharmacophore-Based Virtual Screening . . . . . . . . . . . . . . . . . . . . . . 209 Henrique Barros de Lima, Ana Carolina de Jesus Silva, Carlos Henrique Tomich de Paula da Silva, Carlton Anthony Taft, and Lorane Izabel da Silva Hage-Melim In Silico Studies for the Analysis of Psychedelic Substances with Potential Activity for the Treatment of Epilepsy . . . . . . . . . . . . . . . . . . 235 Natália Reis dos Toscano, Ana Carolina de Jesus Silva, Carlos Henrique Tomich de Paula da Silva, Carlton Anthony Taft, and Lorane Izabel da Silva Hage-Melim Protein–Protein Interaction for Drug Discovery . . . . . . . . . . . . . . . . . . . . . . 255 Beatriz Brambila, Ana Carolina F. S. Martelli, Mariana Pegrucci Barcelos, Solange Cristina Antão, Carlos H. T. P. da Silva, and M. Teresa M. Novo-Mansur SARS-CoV-2 Spike Protein: A Review of Structure, Function, Care, Vaccines, and Possible Inhibitors Designed by Molecular Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Tamara Alice Marinho Coelho, Rai Campos Silva, Suzane Quintana Gomes, and Carlos Henrique Tomich de Paula da Silva Electronic Structure Analysis of Dasatinib Inhibition of Focal Adhesion Kinase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 Daniel Augusto Barra de Oliveira and João Batista Lopes Martins

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Immunobiological Therapies in Rheumatoid Arthritis: Mechanisms of Action and Future Perspectives . . . . . . . . . . . . . . . . . . . . . . . 301 Nascar Katerine do Carmo, Isadora Soares de Lima, Ana Júlia Machado Miranda, Camila Bariani Veloso Viana, Leonardo Luiz Borges, Wilson de Melo Cruvinel, Carlton Anthony Taft, Vinícius Barreto da Silva, and Clayson Moura Gomes Drug-Like Properties of Copaiba Tree Oil-Resin Active Ingredients . . . . 321 Maria Vitória da Silva Paula Cirilo, Gabriel Sousa Albuquerque, Luisa Nunes Sousa, Ana Luiza Bastos Magalhães, Laís Fagundes Carvalho, Alessandra Braga Macedo, Wilson de Melo Cruvinel, Clayson Moura Gomes, Leonardo Luiz Borges, Carlton Anthony Taft, and Vinicius Barreto da Silva In Silico Approaches in Pesticides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 Mariana Pegrucci Barcelos and Carlos Henrique Tomich de Paula da Silva Statistical Approaches Applied to Herbal Product Development . . . . . . . . 353 Monatha Nayara Guimarães Teófilo, Anielly Monteiro de Melo, Clayson Moura Gomes, Vinicius Barreto da Silva, Carlton Anthony Taft, Amanda de Jesus Rocha, Joelma Abadia Marciano de Paula, Wilson de Melo Cruvinel, and Leonardo Luiz Borges Advanced Applications of Lignocellulosic Fibers and Mycelium-Based Composites for a Sustainable World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Regina Geris, Sabrina Calil, Isabel Cristina Rigoli, Rosangela Regia Lima Vidal, Antônio Ferreira da Silva, and Marcos Malta In Silico Design of Acetylcholinesterase and Glycogen Synthase Kinase-3β Multi-target Inhibitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 Leide Caroline dos Santos Picanço, Guilherme Martins Silva, Nayana Keyla Seabra de Oliveira, Lucilene Rocha de Souza, Franco Márcio Maciel Pontes, Isaque Antonio Galindo Francischini, Carlos Henrique Tomich de Paula da Silva, Carlton Anthony Taft, Fabio Alberto de Molfetta, and Lorane Izabel da Silva Hage-Melim Evaluation of the Effect of the Application of Electrical Current in Micromamperage During Alcoholic Fermentation by Saccharomyces Cerevisiae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 Rodrigo Miranda Pires Santos, Gustavo Miranda Pires Santos, Josilene Borges Torres Lima Matos, Fábio Alexandre Chinalia, and Paulo Fernando de Almeida

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Contents

Design of Cannabinoid-Based Drugs for the Treatment of Parkinson’s Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 Mateus Alves Batista, Ana Carolina de Jesus Silva, Carlos Henrique Tomich de Paula da Silva, Carlton Anthony Taft, and Lorane Izabel da Silva Hage-Melim Exploring Innovative Exogenous Green Stimulus Methods for Boosting Bioprocesses: Electric, Magnetic and Ultrasound Stimulation Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 Igor Carvalho Fontes Sampaio, Isabela Viana Lopes de Moura, Pedro Jorge Louro Crugeira, Fábio Alexandre Chinalia, Josilene Borges Tores Lima Matos, Cleveland Maximino Jones, and Paulo Fernando de Almeida

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties for NO Reduction with CO in the Presence of O2 Marcelo Rodrigues, André Luiz Menezes de Oliveira, Elaine C. Paris, Elson Longo, Heloysa M. C. Andrade, and Iêda Maria Garcia dos Santos

Abstract Catalytic systems by which nitrogen oxides (NOx ) in automotive emissions may be reduced to nitrogen are highly efficient when used with rich-burn engines, but are far less effective when excess oxygen is present in the exhaust gases produced, for example, by energy-efficient lean-burn engines. Herein, we describe the synthesis of Sr1-x Nix SnO3 (x = 0 to 0.2) perovskite-type by a modified Pechini method and their capacities to catalyze the reduction of nitric oxide (NO) with carbon monoxide (CO) in the presence carbon dioxide, water vapor and excess oxygen. The materials showed a selectivity of NO reduction rather CO. The highest conversions of NO into nitrogen were observed at temperatures within the range 450–500 °C, with a maximum conversion of 40% attained for the 10% of nickel containing sample. Spectroscopic analyses of the perovskites prior to and following the reduction process revealed changes in the local SnO6 symmetry of the structure followed the formation of strontium carbonate during catalysis. The results also indicate that AO12 and SnO6 sites are both active in the catalytic process, besides being favored by the presence of oxygen vacancies, which adsorbs and activates NO molecules and increase the mobility of lattice oxygen.

M. Rodrigues · A. L. M. de Oliveira · I. M. G. dos Santos (B) NPE/LACOM, Universidade Federal da Paraíba, João Pessoa, PB 58059-900, Brazil e-mail: [email protected] M. Rodrigues Instituto Federal de Educação, Ciência E Tecnologia, Campina Grande, PB 58432-300, Brazil E. C. Paris Empresa Brasileira de Pesquisa Agropecuária, Embrapa Instrumentação, São Carlos, SP 13560-970, Brazil E. Longo Laboratório Interdisciplinar de Eletroquímica E Cerâmica, Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP 13560-905, Brazil H. M. C. Andrade Instituto de Química, Universidade Federal da Bahia, Salvador, BA 40170-290, Brazil © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 C. A. Taft and P. F. de Almeida (eds.), Trends and Innovations in Energetic Sources, Functional Compounds and Biotechnology, Engineering Materials, https://doi.org/10.1007/978-3-031-46545-1_1

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1 Introduction The negative effects of nitrogen oxides (NOx ) on the environment in general, and on the health of animals and humans in particular, are well known. The emission of NOx results principally from the high temperature combustion of gasoline and diesel (internal combustion engines in road vehicles), kerosene oil (gas turbine engines in airplanes) and coal (source of power in many industrial plants). Various catalytic systems have been developed by which nitric oxide (NO) and nitrogen dioxide (the main forms of NOx present in industrial and automotive emissions) may be efficiently reduced to nitrogen. The three-way-catalyst (TWC) currently employed in the majority of road vehicles removes NOx , carbon monoxide (CO), formaldehyde, hydrocarbons and other hazardous air pollutants simultaneously through a series of inter-linked oxidation and reduction reactions. This system is highly efficient when used with rich-burn (or stoichiometric) engines in which the fuel/air ratio is high but is far less effective when excess oxygen is present in the exhaust gases produced, for example, by recently developed energy-efficient lean-burn engines [1–3]. In the last 25 years, the TWCs have been based on platinum, palladium or rhodium, supported on ceria-zirconia materials [4, 5]. Despite being very effective, the high cost of these materials discourages its use and new strategies for the removal of NOx from the exhaust emissions of such engines is required. On the other hand, Brazil is one of the greatest producers of cassiterite, SnO2 , a cheap abundant material, that can be combined to alkaline-earth metals to obtain perovskites. Perovskite is a material with stoichiometry ABO3 , whose structure varies slightly according to temperature and composition [6]. This class of material has been widely studied in materials science due to their technological applications [7]. Our research group evaluated different dopants to improve the catalytic activity of SrSnO3 for NO reduction in the presence of CO [8]. Despite the high conversions obtained after doping, it is well known that real conditions may lead to side reactions, which decrease the catalytic activity. For TWCs, the presence of O2 is certainly an important drawback. In the present work, SrSnO3 :Ni was evaluated for NO reduction by CO in the presence of O2 , in order to evaluate conditions more similar to the real one.

1.1 Crystalline Structure of SrSnO3 Perovskite Alkaline earth stannates, with the general formulae ASnO3 and A2 SnO4 (A = Ca, Sr and Ba) present very interesting properties as recently showed. These compounds received more and more attention in recent years as components of ceramic dielectric elements. The crystalline structures of these perovskites vary according to the modifier cation, which induces different distortions in the lattice, depending on the covalent character of its A-O bond.

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

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Glazer classified the distortions observed into three types: (1) cation displacements, which have important consequences for bulk physical properties; (2) tilting of the BO6 octahedra, which can lead to 23 possible structures, considering a double unit cell; (3) a combination of cation displacement and octahedral tilting [9]. Barium stannate, which has a cubic structure, has bond angles Sn–O–Sn equal 180.0°. The covalent character increase provoked by cation can cause angle reduction values next to 145.0° and, consequently, it can provide the distortion of the SnO6 octahedra. This phenomenon is closely on with the transition of phases in the alkaline-earth stannate perovskites. According to Green et al. [10], SrSnO3 has two bond angles, defined as Sn–O(1)–Sn and Sn–O(2)–Sn, equal to 158.8 and 159.0° at room temperature, respectively. Mizoguchi et al. [11] reported that these angles are approximately 159.0° and 159.2°. For both papers, the positional and thermal parameters were obtained using Rietveld refinement and indicated the presence of an orthorhombic structure with space group Pbnm (SG No . 62). Vegas et al. [12], using geometrical considerations due to the presence of heavy twinning, also reported that the SrSnO3 is orthorhombic with space group Pbnm. The twinning nature, studied by transmission electron microscopy, provided the first evidence for the likely existence of high temperature structural phase transitions in SrSnO3 . Green et al. [10] and Mountstevens et al. [13, 14] corroborated these results and confirmed that Pbnm superstructure involves in-phase tilting of SnO6 octahedra about the c-axis and out-of-phase tilting about the diad axis parallel to the b-axis. They observed that a continuous change in the symmetry in SrSnO3 , with phase transition from Pbmn to Imma at 636 °C, with no symmetry discontinuity, since it involves loss of the in-phase tilting. The lattice parameters vary continuously through the transition, but their divergence on heating towards the transition is very unusual. Glerup et al. [15] used differential scanning calorimetry (DSC) and dilatometry to prove the existence of structural phase transitions in strontium meta-stannate. The I4/mcm superstructure is a common intermediate between orthorhombic and cubic perovskites. The SnO6 octahedra in this phase are slightly tetragonally compressed with the axial Sn–O(1) bonds 0.002 Å shorter than the equatorial Sn–O(2) bonds. This tetragonal compression is consistent with studies on other I4/mcm perovskites [16–19]. Alkaline earth stannates have been synthesized by different methods [20]: solid state reaction with heat treatment temperature above 1200 °C, combustion, hydrothermal method and polymeric precursor method, derived from Pechini method. The phase equilibria in the SrO-SnO2 system have been studied by several authors [21] that synthesized SrSnO3 and Sr2 SnO4 by the peroxo method. SrSnO3 , the most important of these compositions, is a dielectric material of technological importance and it has been used as humidity sensor, when reported the synthesis of SrSnO3 by means of the precipitation of hydrated SrSn(OH)6 , followed by a heat treatment at 950 °C for 14 h to produce anhydrous SrSnO3 [22] and as photocatalyst [23]. It is normally synthesized at temperatures above 1000 °C by

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solid-state reaction between SrCO3 or SrO and SnO2 . The relatively high preparation temperatures lead often to powders of large and varied grain sizes and varying impurity content. In the present study, the polymeric precursor method was used as the synthesis route. This method, initially developed by Pechini [24], has many advantages, as chemical homogeneity of multicomponents at the molecular scale; direct and precise control of stoichiometry in complex systems at relatively low temperatures; possibility of obtaining nanometric particles and processing simplicity. Moreover, the polymeric precursor method is very flexible, being used to prepare different systems, with different structures.

1.2 ASnO3 Perovskites as Catalyst for NO Reduction Recently there has been interest in the alkaline earth stannates (ASnO3 ), for use as adsorbent and catalysts in the reduction processes of NOx , in lean exhaust gases [25–27]. The nitrogen oxide gases are trapped on a selective adsorbent such as the stannates and then reduced using a small burst of fuel or recirculated to the engine to be thermally destroyed. BaSnO3 is particular promising as a selective adsorbent. Perovskite-type mixed oxides containing lanthanum are able to catalyze the efficient reduction of NOx [28–33], while the adsorption of NOx by zirconate, titanate and stannate perovskites has been investigated in some detail [34, 35]. The key factors that control this type of adsorption on the alkaline earth perovskites are the energy of the B-O bond and the electropositivity of the A cation, such that barium > strontium > calcium. On this basis, the adsorption on zirconates and titanates would be much lower than that observed on stannates. Ishihara et al. [26, 27] employed the mixed oxides BaSnO3 -WO3 and SrSnO3 -WO3 as capacitive-type NO sensors, and observed significant sensitivity even at 550 °C, a temperature that is considered to be relatively high for the process of NO adsorption. Interestingly, the addition of platinum was effective in improving the response characteristics of the sensors. A number of studies have focused on the potential of BaSnO3 as a NOx storage catalyst [34, 35], while SrSnO3 has been shown to catalyze the reduction of NO by ethylene with a conversion of 8% at 600 °C [36]. Recently, our research group reported the use of SrSnO3 modified with transition metals, for NO reduction by CO [8]. The catalytic conversion of NO into N2 was improved from 10%, for pure SrSnO3 , to 100% for SrSn0.95 Ni0.05 O3 . Conversions of 85% of NO into N2 and 90% of CO into CO2 were obtained for Ni doped samples at 600 °C. In the present study, mixed oxides with x = 0 to 0.20 were obtained using a soft chemical method and were evaluated for their capacities to catalyze the reduction of NO by CO in the presence of carbon dioxide (CO2 ), water vapor and excess oxygen.

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2 Experimental 2.1 Preparation of Perovskites The salts and reagents used in the synthesis of the perovskite phase, SrSnO3 :Ni, are listed in Table 1. The samples were prepared by the modified Pechini method. Tin citrate was obtained using the procedure described in literature [37, 38], and it was used in the preparation of the polymeric resins. After citrate synthesis, the Sr(NO3 )2 salt was slowly added to citrate, until its total dissolution. A 3:1 citric acid:metal molar ratio was used in order to guarantee the complete metal chelation. Then, ethylene glycol was added to the solution and a 60:40 citric acid:ethylene glycol mass ratio was used. The temperature reaction was raised to about 80 °C, leading to the polymerization process. This resin was heated up to 300 °C in air to obtain the powder precursor. The precursors were de-agglomerated in a 200 mesh sieve. The thermal characterization of these precursors was done by thermogravimetry (TG) and differential thermal analysis (DTA). The thermal characterization was done using a TA instruments—SDT 2960 thermal analyzer. About 10 mg of samples was placed into alumina pans and heated at 10 °C min−1 up to 1200 °C, in air atmosphere, with a flow rate of 100 mL min−1 . Powder precursors were calcined in air atmosphere at 400 °C for 4 h, followed by heating up to 700, 800 or 900 °C for 4 h, with a heating rate of 5 °C min–1 . The phase composition of the samples was characterization by X-ray Diffraction (XRD) using a Siemens D-5000 diffractometer and Cu Kα radiation. Using XRD data, FWHM of the (200) peak of perovskite was calculated and lattice parameter was determined using Rede 93 program. FWHM of the (200) peak of the perovskite was determined, by fitting using Gaussian curves. Relative crystallinity was evaluated in order to compare the behavior of the different samples in relation to crystallization. Calculation was done using the peak intensities according to Eq. 1; C R(%) =

I − I0 ∗ 100 I100 − I0

(1)

Table 1 Precursors used in the synthesis of SrSnO3 :Ni, by the modified Pechini method Reagent

Chemical Formula

Purity %

Manufacturer

Citric acid—CA

C6 H8 O7 .H2 O

99.5

Cargill

Ethylene glycol—EG

HO.CH2 .CH2 .OH

99.0

Vetec

Nickel (II) acetate tetrahydrate

(CH3 COO)2 Ni · 4H2 O

98.0

Avocado

Strontium nitrate

Sr(NO3 )2

99.0

Vetec

Tin chloride dihydrate

SnCl2 · 2H2 O

99.0

Aldrich

Ammonium hydroxide

NH4 OH

99.0

Nuclear

Nitric Acid

HNO3

65.0

Dinâmica

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where: I = intensity of the (200) peak of the XRD pattern; Io = intensity of the (200) peak of the lowest crystalline sample; I100 = intensity of the (200) peak of the most crystalline sample. Crystallite size was calculated using Scherrer equation. In the present case, quartz was used as external standard. Infrared analyses were done in a MB 102 Bomem spectrometer, using KBr pellets, in the range from 4000 to 400 cm−1 . Micro-Raman measurements were performed using a Jobin–Yvon model T64000 Triplemate spectrograph. A Coherent Innova 70C Ar-Kr laser and a Raman microprobe with 50 X objective were employed to focus 647.0 nm radiation onto the sample, and the scattered light was collected using a charge-coupled device (CCD) system. A Bel Japan Belsorp-mini II volumetric adsorption measurement instrument was used to determine the BET specific surface area of the perovskites. In each case, samples were degassed under vacuum for 0.5 h at room temperature prior to the introduction of nitrogen at 77 K. TPR-H2 analysis were performed in a Micromeritics, Pulse Chemisorb model AutoChem 2920, using 60 mg of sample placed in a type “U” quartz reactor and heated up to 200 °C for 0.5 h under nitrogen flow (50 mL min−1 ), with a heating rate of 10 °C min−1 . After pretreatment, the sample was cooled to room temperature and heated again up to 1000 °C with the same heating rate under a flow of a 5% of H2 in N2 (V/V) mixture. The consumption of reducing agent was monitored using a thermal conductivity detector.

2.2 Catalytic Activities A continuous flow U-tube micro-reactor, operating at ambient pressure, was used to investigate the capacities of the perovskites to catalyze the reduction of NO by CO in the presence of CO2 , water vapor and excess oxygen. Prior to testing, the perovskite sample (0.1 g) was heated under helium flux at a rate of 10 ºC min−1 and treated at 500 °C for 1 h. The feed gas, which contained NO (5000 ppm), CO (1%), CO2 (5%), water (10%) and oxygen (5%) with helium balance, was passed through a glass saturator containing water at an appropriate temperature to obtain 10% mol/mol of vapor in the system. Reactions were carried out within the temperature range 300— 600 °C and with a feed-gas flow-rate of 200 mL min−1 . Steady state conversions were determined after triplicate analysis at each reaction temperature with standard deviation less than 5%. The exit gas stream was diverted into a Shimadzu model GC-17A gas chromatograph equipped with a Carboxen column, and the amounts of nitrogen, CO and CO2 were determined from the chromatograms so-recorded.

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

7

3 Results and Discussion 3.1 Characterization of SrSnO3 :Ni The thermal analysis results of the powder precursors are presented in Fig. 1. In the thermogravimetric curve, Fig. 1a three thermal decomposition steps were observed. The first one was attributed to the loss of H2 O and some gases adsorbed on the surface of the powder [39]. The second and third steps were ascribed to the elimination of the organic matter, when the polymer is transformed to CO2 and H2 O. The DTA curve, Fig. 1b, indicates the presence of exothermic peaks. These peaks overlap with the second decomposition step of the TG curves, indicating the combustion of the organic material. The first exothermic peak, at 348 °C is related to the combustion of small organic chains or of smaller particles. The peak with highest intensity was observed at 416 °C, besides a shoulder at 477 °C. The presence of wide peaks indicates the existence of a particle size distribution, as the polyester breakage can occur in different ways. The Fig. 2 shows the IR spectra of the pure SrSnO3 , calcined from 600 to 1000 °C. Orthorhombic SrSnO3 has 57 normal modes at q = 0, with 25 infrared active modes, Γ IR = 9B1u + 7B2u = 9B3u . According to the literature the vibrations of the stannate group (SnO3 2− ) produce high intensity infrared absorption bands in the ranges of 300—400 and 600–700 cm−1 , with the stretching vibration of the Sn–O bond at about 674 cm−1 and 530 cm−1 [39, 40]. The infrared spectrum of SrSnO3 after calcination at 600 °C indicate that the band related to the Sn—O bond is very broad, with a low definition, due to the low short range-order of this sample. At 700 °C, two intense well-defined bands are observed, the first one at 664 cm−1 and the second one below 400 cm−1 . At 800 and 900 °C, bands with lower intensity are observed at 664 and 540 cm−1 . At 1000 °C, a dislocation of the main band to 658 cm−1 occurs, besides the decrease of

(a)

100 o

221 C o

Step 348 C

Massa Loss (%)

nd

2

19.37%

70

3

nd

Step

60

o

417 C

50 o

20.81% 4

40

th

200

400

80 70 60

348

477

50

690 C

Step

40

30 0

(b)

416

90

11.39%

80

100

DTA (u.a.)

Massa Loss (%)

90

600

Temperature ( o C)

800

1000

1200

30 0

200

400

600

800

1000

1200

o

Temperature ( C)

Fig. 1 Thermal analysis profiles of the powder precursor of the SrSnO3 . a TG curve, with the different decomposition steps; b Superposed TG/DTA curves

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Fig. 2 Infrared spectra of the pure SrSnO3 , calcined at different temperatures

the intensity of the band at 540 cm−1 . The change in the profiles may be associated to SnO6 octahedral rearrangement. According to Nakamoto [41] and Licheron [42], the two main bands characteristic of strontium carbonate are observed at 870 and 1430 cm−1 . According to Nyquist and Kagel, carbonate bands are observed at 1320–1530 cm−1 (strong), 1040–1100 cm−1 (weak) and 800–890 cm−1 (weak-medium) [43]. In the present case, these bands are observed at about 1450, 1080 and 860 cm−1 . The intensities of these bands do not decrease even after calcination at 1050 °C. Figure 3 presents the XRD patterns of SrSnO3 , after thermal treatment at different temperatures. Results indicate that the heat treatment at 600 °C already leads to crystalline perovskite phase, superposed to a broad band indicative of an amorphous phase. Increasing the heating temperature to 700 °C resulted in the vanishing of this broad band, besides the high crystallinity of SrSnO3 perovskite. Strontium carbonate is observed as secondary phase. The calculated lattices parameters for the synthesized samples are listed in Table 2 and agree with literature data. At first sight, no meaningful differences are observed among the patterns of the perovskite phase, calcined at different temperatures. A careful insight of the materials was obtained by deconvolution of the (200) peak. The full width at half maximum (FWHM) of the XRD peaks is an importante estimate of the long range order of a crystalline structure—the smaller the value of FWHM, the more ordered the structure. The increase of the temperature provides a bigger mobility to atoms in the lattice, causing the growth of the crystallites and the ordering of the lattice, as indicated in Fig. 4. The highest crystallinity is observed after calcination at 1050 °C, as expected. The Rietveld refinement of samples heat treated at 900 and 1050 °C, obtained using the GSAS program, confirmed the orthorhombic structure of SrSnO3 (space group Pmcn). It was not possible to obtain reliable data for samples calcined at 700 and 800 °C, as indicated by the RBragg values (not shown), while reliable data were obtained for samples calcined at 900 and 1050 °C [44, 45]. Lattice parameters and phase percentages obtained by Rietveld refinements are displayed in Table 3 (Fig. 5).

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

9

Fig. 3 XRD patterns of SrSnO3 , calcined at different temperatures. (#) SnO2 , (*) SrSnO3 , (+) SrCO3 Table 2 Structural parameters for SrSnO3 at different temperatures in previous works Structures

Synthesis method

Lattices parameters (Å) a

b

Orthorhombic Pbnm

Solid state reaction

5.7079

5.7035

Modified Pechini method

[Ref.]

c

Synthesis temperature (o C)

8.0645

1360–1400

[15]

5.702

5.712

8.086

1360–1400

[15]

5.7586

5.7455

8.1127

700

[19]

5.7077

5.6982

8.0641

1350

[42]

5.7089

5.7034

8.0648

1300

[10]

5.7082

5.7035

8.0659

1300

[25, 37]

5.687

5.684

8.190

700

This work

5.696

5.690

8.126

800

This work

5.700

5.700

8.039

900

This work

5.700

5.700

8.052

1050

This work

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Fig. 4 Evaluation of crystallization process of SrSnO3 as a function of calcination temperature

In this paper, the Raman spectroscopy was used to confirm the structure and evaluate the short-range order of the materials, Fig. 6. There are 24 Raman active modes at q = 0 with Γ Raman = 7Ag + 5B1g + 7B2g + 5B3g [46]. Hodjati et al. [25] revealed the 11 Raman-active modes predicted with factor group analysis for orthorhombic perovskite (space group Pbnm), appearing at 119, 150, 168, 220, 257, 305, 403, 511, 596, 713, and 890 cm−1 . At 600 °C, the Raman spectrum (not shown) presents a very low definition. When calcination temperature increases, a higher short-range order is observed, indicating a higher symmetry. The spectrum of pure SrSnO3 , calcined at 700 °C (Fig. 6) is already characteristic of the perovskite phase. Bands assigned to strontium carbonate (SrCO3 ) may also be identified around 146 cm−1 , 183 cm−1 , 700 cm−1 and 1072 cm−1 [47]. The band assigned to rutile (SnO2 ) may also be identified at 631 cm−1 (A1g mode) [48], in agreement to XRD patterns. Other band identified at around 980 cm−1 (broad and small) was not identified. In relation to the peaks assigned to perovskite phase, assignments are presented in Table 4, with the peaks found in the present work. According to Moreira et al. [40], the peak at 223 cm−1 (Ag mode) corresponds to the scissors movement of Sn–O–Sn groups along the c axis; the peak at 90 cm−1 (Ag mode) is related with the bending of O–Sn–O groups within the ab plane and the simultaneous movement of Sr ions along the b axis; the peak at 259 cm−1 is related to O–Sn–O bending within the ab plane. The broad band at about 570 cm−1 has been related to distorted SnO6 octahedra, due to the presence of oxygen vacancies [8]. The intensity of this band (around 570 cm−1 ) decreases continuously, disappearing after calcination at 1050 °C, indicating the higher short-range order of this sample.

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

11

Fig. 5 Results of the Rietveld refinement from XRD patterns of SrSnO3 calcined at a 900 °C; b 1050 °C

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Table 3 Results of rietveld refinements from XRD patterns of SrSnO3 900

Calcination temperature (°C) Lattice parameters Pmcn

a

1050 8.070363

b

5.719478

5.716411

c

5.706151

5.705265

Unit cell volume (Å3 ) Phase amount (mass %)

8.067167

SrSnO3

263.282

263.204

89.653

95.892

SnO2

4.9501

3.3198

SrCO3

5.3973

0.78870

RBragg (%)

3.10

1.98

RP (%)

4.74

4.43

RWP (%)

5.72

5.77

Chi2

1.332

1.695

Fig. 6 Micro-Raman Spectra of the pure SrSnO3 calcined at different temperatures. (#) SnO2 , (+) SrCO3 , (*) SrSnO3

According to Mizoguchi et al. [11], SrSnO3 is distorted from cubic symmetry by an octahedral tilting distortion. In these compounds, the local octahedral environment about Sn4+ is maintained, and the corner-sharing octahedral connectivity of the perovskite structure is also preserved, but tilts of the octahedra lead to significant changes in the environment about the A-site cation (Sr2+ ) as well as the oxygen anion. This change is driven by a mismatch in the fit of the A-site cation to the cubo-octahedral cavities in the corner-sharing octahedral network.

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

13

Table 4 Frequencies (cm−1 ) of unpolarized Raman bands and their assignments for SrSnO3 Mode

Ref. [53]

Ref. [40]

This work 700

800

900

1050

Lattice mode

119 150 168

89 121 147 166

90.8 117.8 151.2 173.4

92.3 117.0 150.8 172.7

91.9 117.4 152.0 172.3

91.5 116.2 152.4 171.9

Bending modes

220 257 305

223 252 302

224.4 260.0 307br

225.2 260.0 307br,sm

224.1 259.6 307br,sm

224.1 260.8 308 br,sm

Torsional modes

403 511 596

381, 390 446

403.6 516 577.3

403.7br 573.7

404.8br 521 577.3

403.5 516br,sm

Stretching modes

713 890

645, 701

701.3 893br,sm

700.2

699.9 891br,sm

701 889br

Table 5 Calculation of band gap values of SrSnO3 calcined at different temperatures

Temperature (o C)

Correlation coef. (r2 )

Band gap (eV)

700

0,994

3,8

800

0,996

3,8

900

0,993

3,7

1050

0,995

3,7

In this work, the experimental band gap values were calculated according to the Tauc method [49], from the UV–visible spectra. Values are displayed in Table 5 and agree to Mizoguchi results [11], who obtained an experimental gap value of 4.1 eV, for SrSnO3 synthesized by solid state reaction. No meaningful difference among the band gap values was observed as a function of temperature. The XRD patterns associated to the Raman spectra indicated that samples calcined at 700 °C already display a high crystallinity and high short-range order. For these reasons, this calcination temperature was chosen for the synthesis of the solid solutions containing nickel, with stoichiometry Sr1-x Nix SnO3 (x = 0 to 0.2). XRD patterns of the modified samples are displayed in Fig. 7. All samples had an orthorhombic structure, with small amounts of SnO2 and SrCO3 as secondary phases. More details about the synthesis of these materials were previously published by our research group [50].

3.2 Catalytic Activity of SrSnO3 :Ni Results of the reduction of NO by CO, using SrSnO3 as catalyst are displayed in Fig. 8. This reaction is stoichiometric with a molar ratio of 1:1, as displayed in Eq. 2.

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Fig. 7 XRD patterns of the samples Sr1-x Nix SnO3 (x = 0 to 0.2) calcined at 700 °C. (#) SnO2 , (+) SrCO3 , (*) SrSnO3

The very different conversions observed in Fig. 8 indicate that side reactions occur and part of CO oxidation is due to its reaction with O2 (Eq. 3), as expected. Previous tests in the absence of impurity gases performed by our research group [8] indicated an activity of about 35% for SrSnO3 , while only 15% of NO conversion into N2 was obtained in the present work. Despite the smaller conversion, this result is more realistic, considering real conditions. NO(g) + CO(g) → N2 (g) + CO2 (g)

(2)

2 CO(g) + O2 (g) → 2 CO2 (g)

(3)

The capacities of Sr1-x Nix SnO3 (x = 0 to 0.2) to catalyze the reduction of NO by CO are presented in Fig. 9. The results indicate that the amount of nickel present in the perovskite represents an important parameter in the catalytic process. After nickel addition, NO conversion reached 40% at 500 °C, for sample SrSn0.9 Ni0.1 O3 , which is a 2.7-fold increase, comparing to SrSnO3 . Moreover, nickel addition also decreased the temperature of maximum conversion of CO, from 600 °C to 450 °C for sample SrSn0.85 Ni0.15 O3 . This result indicates that SrSnO3 :Ni may also catalyze the CO oxidation by O2 . Additionally, although the surface areas presented by the perovskite samples varied between 51 and 60 m2 g−1 according to the amount of nickel present, the results clearly show that catalytic efficiency is not related simply to particle size since materials with similar surface areas presented different conversion levels. The variation in NO conversion as a function of the amount of dopant was much reduced at 450 °C, even though the highest conversion efficiency was not observed at this temperature. Less than 1% of N2 O and NO2 was observed below 400 °C and were not detected at higher temperatures. In previous studies concerning the perovskite-catalyzed reduction of NO by CO, the mixed oxides employed typically contained lanthanum as one of the cations. In general, the rates of conversion of NO that can be obtained with such materials are

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

15

Fig. 8 Conversion (%) of NO into N2 (due to the reaction displayed in Eqs. (2)) and CO into CO2 (due to the reactions displayed in Eq. (2 and 3)), over SrSnO3 as a function of temperature

Fig. 9 Conversion (%) of NO into nitrogen and CO into CO2 over Sr1-x Nix SnO3 (x = 0 to 0.2) as a function of temperature

higher than those reported here for Sr1-x Nix SnO3 . In this context, Leontiou et al. [51] have reported optimal sensitivity of La1−x Srx FeO3±δ at temperatures in the range 450–550 °C. However, a major disadvantage of lanthanum-based perovskites is the high cost of the rare earth, the availability of which is decreasing day-by-day [28]. It is also worthy of note that most of these earlier studies evaluated NO reduction by CO [28–33], while others also investigated the influence of oxygen on the catalytic process [34–36]. In the present work, the reduction of NO by CO has been assessed

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M. Rodrigues et al.

under conditions that are similar to those found in actual exhaust gases, namely, in the presence of CO2 , water vapor and oxygen.

3.2.1

Catalytic Mechanism

In order to study the process of NO reduction in detail, the catalysts were analyzed by IR spectroscopy, XRD and Raman spectroscopy both prior to and following reaction. The IR spectra (Fig. 10a–f) revealed vibrations associated with the Sn–O bond at 600–700 cm−1 , while carbonate bands were observed around 856, 1090 and 1460 cm−1 . The intensities of the carbonate bands increased in all samples after the catalytic reaction. Similar results were observed in the XRD patterns, as displayed in Fig. 11. The formed carbonate may be derived from two distinct sources, namely, CO2 and CO, since both can be adsorbed onto the surface of the catalyst. According to the results shown in Fig. 8, not all of the CO was converted into CO2 during the catalytic process since the CO to CO2 ratio was not always stoichiometric but varied according to the temperature and the catalyst. Where the quantity of CO consumed during the catalytic process exceeded the amount of CO2 formed, it is likely that part of the CO had been converted into carbonate. In alternative cases, the higher amount of CO2 could probably be attributed to the decomposition of previously formed carbonate. In the Raman spectra (Fig. 12a–f) recorded prior to reaction, the expected perovskite bands were observed together with absorptions at 148, 183, 248 and 700 cm−1 that could be assigned to SrCO3 [47], while 635 cm−1 mode can be assigned to the SnO2 . Active modes related to the orthorhombic perovskite were also observed at about 89.5, 102, 121, 141, 143, 223, 251, 258, 311, 359, 449 and 573 cm−1 in the pure SrSnO3 , as observed in Fig. 6. Furthermore, the spectra revealed that the addition of Ni2+ created significant changes in the former region (SnO6 ), indicating that replacement occurred at the Sn4+ site leading to the formation of oxygen vacancies. Thus, alongside the original SnO6 band present at around 570 cm−1 in undoped SrSnO3 (Fig. 12a), a second band at ~ 650 cm−1 was observed. This additional band was attributed to the change in symmetry of the BO6 octahedron arising from the formation of oxygen vacancies and the presence of two different cations at the same site [52]. As a consequence of the presence of oxygen vacancies, the Sn4+ ions with sixfold coordination that were present in the original structure would be accompanied by Sn4+ ions with fivefold coordination. Such fivefold polyhedra may present different charges by virtue of the oxygen vacancies, since it has been shown that such defects can be differentially ionized [53]. The effects Ni2+ to SrSnO3 addition were described using the Krogër-Vink notation [54], as displayed in Eqs. (4 to 6) Ni O

Sr Sn O3

→

" N i Sn + VO •• + Oox

(4)

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

17

Fig. 10 Infrared spectra of Sr1-x Nix SnO3 (x = 0 to 0.2) catalysts, recorded before and after the catalytic reaction

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M. Rodrigues et al.

Fig. 11 XRD patterns of Sr1-x Nix SnO3 (x = 0 to 0.2) catalysts, recorded before and after the catalytic reaction. (* SrSnO3 , # SnO2 , + SrCO3 )The formed carbonate may be derived from two distinct sources, namely, CO2 and CO, since both can be adsorbed onto the surface of the catalyst. According to the results shown in Fig. 8, not all of the CO was converted into CO2 during the catalytic process since the CO to CO2 ratio was not always stoichiometric but varied according to the temperature and the catalyst. Where the quantity of CO consumed during the catalytic process exceeded the amount of CO2 formed, it is likely that part of the CO had been converted into carbonate. In alternative cases, the higher amount of CO2 could probably be attributed to the decomposition of previously formed carbonate

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

19

Fig. 12 Raman spectra of Sr1-x Nix SnO3 (x = 0 to 0.2) catalysts, recorded before and after taking part in the catalytic reduction. (* SrSnO3 , # SnO2 , + SrCO3 )

The state [Sn O5 · VO x ]c , , where c indicates the complex, is neutral being able to donate an electron (donor state; Eq. 5), the state [Sn O5 · VO •• ]c has a double positive charge and is able to capture an electron (acceptor state), while the state [Sn O5 · VO • ]c has one positive charge and can donate or accept an electron (Eq. 6). On this basis, Lewis acid or Lewis base sites are formed depending on the oxidation state of the oxygen vacancy [53].

20

M. Rodrigues et al.

[

] [ , + [Sn O6 ]cx → [Sn O6 ]c + Sn O5 · VO• c [ ] ] [ , Sn O5 · VOx c + [N i O6 ]cx → Sn O5 · VO• c + [N i O6 ]c [ ] ] [ , Sn O5 · VO• c + [Sn O6 ]cx → N i O5 · VO•• c + [Sn O6 ]c [ ] ] [ , Sn O5 · VO• c + [N i O6 ]cx → N i O5 · VO•• c + [N i O6 ]c Sn O5 · VOx

]

c

(5)

(6)

Additionally, previous studies of noble metal oxides have indicated that oxygen vacancies are very important in the reduction of NO since they increase oxygen mobility, and catalytic activity is improved when such vacancies are disordered [55]. In doped perovskite structures, such defects are present in high amounts making NO adsorption easier. In the Raman spectra recorded after the catalytic process, the intensity of the SnO2 bands showed a general increase indicating that destabilization of the structure had occurred following NO and CO adsorption. Additionally, increases in the intensity of the band at ~ 425 cm−1 attributed to torsional mode vibrations of SnO6 were also observed. The spectra of pure SrSnO3 and of SrSnO3 :1% Ni2+ recorded after the catalytic process showed no meaningful differences as the same absorption bands were observed for both spectra, with a dislocation to higher energy values in the system containing nickel. However, the band at ~570 cm−1 appeared broader after the catalytic process indicating that an increase in short range disorder may have occurred. When amounts of Ni2+ exceeded 5%, meaningful changes could be observed in the Raman spectra. Thus, intensities of the SnO6 bands (~570 cm−1 ) decreased while the intensities of the bands assigned to asymmetry (~620 cm−1 ) remained high, indicating that BO6-x sites may be active for NO adsorption. In theory, NO may be adsorbed onto the surface of a metal oxide in one of three different electronic configurations, namely, NO+ , NO− or NO. In terms of NO decomposition, NO− should be the active form while NO+ should be inactive since N–O bond strength increases in the order NO− < NO < NO+ [35]. Moreover, when NO− is adsorbed onto the oxide surface, only one bond is broken in the desorption of nitrogen oxides and this should be reflected in a much lower desorption temperature than for NO+ in which two bonds must be broken [56]. The kinetics of NO decomposition on the perovskites La0.8 Sr0.2 CoO3 and La0.4 Sr0.6 Mn0.8 Ni0.2 O3 have been studied in some detail by Teraoka et al. [57]. The results revealed that molecular NO was adsorbed onto the mixed oxide together with one oxygen atom, and that NO− formed by electron flow from a B-site cation with the concomitant oxidation of the cation (i.e. Co3+ → Co4+ , Mn3+ → Mn4+ or Ni2+ → Ni3+ ). Following adsorption of a second molecule of NO, molecular nitrogen was produced and eventually released into the gas phase by the interaction of two NO− species. The reaction was virtually first-order with respect to NO and was inhibited by oxygen. Yamamoto et al. [58] studied the capacities of various mixed oxides, specifically, Cu, CuO, Cu2 O, Sn and Ag deposited on Al2 O3 , to catalyze the reduction of NO by CO in the presence of oxygen. Since the reduction of NO by CO and the oxidation of CO by oxygen are competitive reactions, the presence of oxygen in the NO–CO

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

21

system suppresses nitrogen formation. The degree of suppression was found to be different for the various loaded elements, and many of the catalysts studied were inactive at ratios of CO to oxygen of less than 0.5. The highest NO conversions were obtained with Ag and Sn deposited on Al2 O3 . According to Dekker et al., [59], alumina-supported copper and copper-chromium catalysts are only able to bring about the conversion of NO by CO in the presence of oxygen when they are in a reduced state, thus implying that NO conversion is not only limited by gas phase oxygen but also by subsurface oxygen. However, these authors were able to demonstrate that when the gas composition passing over the oxidized catalyst was changed to CO/NO/helium, a peak of nitrogen production was observed immediately owing to the rapid adsorption of NO onto the oxidized sites. Evidence obtained in the present study indicates that NO adsorption onto SrSnO3 :Ni2+ is also associated with oxygen vacancies present in oxidation states such as [B O5 · VO • ]c , where B is most probably Sn4+ or Ni2+ , which may donate an electron to NO leading to the formation of NO− and, consequently, of [B O5 · VO •• ]c (Fig. 13). Moreover, the SrCO3 formation after the perovskite had been subjected to the catalytic reaction strongly suggests that CO adsorption occurs on the Sr2+ sites. The TPR-H2 profile of the samples SrSnO3 ; Sr0,099 Ni0,01 SnO3 ; Sr0,095 Ni0,05 SnO3 ; Sr0,090 Ni0,10 SnO3 and Sr0,080 Ni0,20 SnO3 are showed in Fig. 14a to e. According to the literature, no reduction is observed for Sr2+ in the temperature range from 25 to 1000 °C [60], while Sn4+ may be reduced to the metallic specie in this same temperature range as showed in Eq. 4 [61, 62]. According to Melo et al. [63], the reduction of solids in H2 atmosphere is related to the electrochemical process with possibility of releasing oxygen. Sr Sn O3 + H2 → Sr O + Sn O + H2 O

Fig. 13 Schematic view of the process of NO adsorption on a SnO5 cluster

(7)

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M. Rodrigues et al.

Fig. 14 TPR-H2 profile for systems: a SrSnO3 ; b Sr0,099 Ni0,01 SnO3 ; c Sr0,095 Ni0,05 SnO3 ; d Sr0,090 Ni0,10 SnO3 ; e Sr0,080 Ni0,20 SnO3 and f all samples

SrSnO3 :Ni Perovskites: Synthesis, Structure and Catalytic Properties …

23

Sr Sn O3 + 2H2 → Sr O + Sn + 2H2 O

(8)

In SrSnO3 system, the reduction process of Sn4+ may occur in two steps. The first peak is observed around 345 ºC, probably due to the reduction of Sn4+ to Sn2+ , as well as to the beginning of the reduction of Sn4+ to Sn0 . The peaks between 500–600 °C can be attributed to the bulk reduction, Sn4+ and/or Sn2+ to metallic tin. While at high temperatures peaks centred at 796 z C were related to the reduction of Sn4+ /Sn3+ to Sn2+ and the reduction of Sn2+ to Sn0 , which is in line with earlier observations for SnO2 [64, 65]. The reduction of Sn4+ promotes an unbalance of charge in the system being compensated by the formation of oxygen vacancies, neutralizing the system. After nickel addition, a dislocation of the reduction peaks to smaller temperatures is clearly observed. Moreover, the increase of the shoulder on the left side of the reduction band is also noticeable. This may be related to Ni(II) reduction, as the reduction temperature profile of the NiCo systems exhibits two peaks, at 400 z C and 850 z C, which are attributed to NiO [66, 67]. These results confirm that nickel addition into the SrSnO3 lattice favors redox process.

4 Conclusion Perovskite-type mixed oxides of the form SrSnO3 :Ni2+ were synthesized by the modified Pechini method. Doping SrSnO3 with Ni2+ led to the formation of oxygen vacancies through Sn4+ replacement and as consequence, these materials were able to catalyze the reduction of NO by CO in the presence of oxygen. IR and XRD spectra recorded prior to and after catalysis revealed that adsorbed CO and CO2 reacted with oxygen in the lattice leading to the formation of carbonates. Raman spectra showed that SnO2 was formed during the catalytic process, while changes observed in the former region (SnO6 ) suggested that BO6-x were the active sites for NO adsorption. The TPR-H2 profiles showed that part of the Sn4+ and of the Ni2+ can be reduced, keeping the perovskite structure intact. This reduction can be partial or even complete, for Sn4+ . This process leads to the formation of oxygen vacancies to guarantee the system electroneutrality. Additionally, the formation of oxygen vacancies assisted in the diffusion of oxygen, thus facilitating the oxidation of CO to CO2 and the reduction of NO to N2 . Acknowledgements The authors acknowledge the Brazilian funding agencies: Financiadora de Estudos e Projetos (FINEP/MCTI), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/MEC) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq/ MCTI) for financial support of this study.

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Overview: Photovoltaic Solar Cells, Science, Materials, Artificial Intelligence, Nanotechnology and State of the Art Carlton Anthony Taft and Jose Gabriel Solano Canchaya

Abstract Since the sun can provide all the renewable, sustainable energy we need and fossil fuels are not unexhaustible, multidisciplinary scientists worldwide are working to make additional sources commercially available, i.e., new generation photovoltaic solar cells (PVScs), with novel technological properties. We overview the field of PVScs indicating actual state of the art as well as future trends and perspectives. We summarize the fundamental science of PVScs, ShockleyQueisser limit, generations, technological devices including (heterojunctions, multijunctions, tandem, multiple exciton generation, quantum dots, panels, arrays and power systems). Materials for PVScs including (inorganic semiconductors (Si, GaAs, CdTe, CIGS…), organic (small molecules, fullerenes, nonfullerenes, fused ring acceptors, non-fused ring electron acceptors, all polymer, polymer-small molecule acceptors); hybrid organic–inorganic (HOI), perovskite (Pe), Ruddelson-Popper phase (RP) Pe, Dion-Jacobson (DJ) phase Pe, dye synthetisized (DS), quantum dot (QD), colloidal QD (CoQD), QDDS, QDPe, QDHOI, core/yolk (shell), two dimensional nanolayers (2d-NL), graphene (G), graphene oxide (GO), reduced graphene (rGO), graphite, nanographite, carbon nano/quantum dot, graphene quantum dot (GQD), black/blue phosphorous, transition metal dichalcogenides (TMDCs), g-C3 N4 (graphitic carbon nitride), low dimensional boron nitride (BN), Janus-like nanocrystals, one-dimensional photonic crystal (1DPC), MXene, two dimensional van der Waals heterostructures (2d-vdWHs), borophene monolayer, nanowire, nanotubes, nanorods, nanofiber, tetrapods as well as semi-transparent, ultra-thin, ultra-light, flexible, 3d printable PVS cells/panels that work within technological-based devices. Notably, nanotechnology and artificial intelligence should play important roles in PVScs whereas quantum dots/nanomaterials based Scs including QDDS, QDPe and C. A. Taft (B) Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil e-mail: [email protected] J. G. S. Canchaya Grupo de Métodos Computacionais Aplicados a Nanomateriais, Nacional University of San Marcos, Lima, Peru Graduate School, Universidad Continental, Lima, Peru © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 C. A. Taft and P. F. de Almeida (eds.), Trends and Innovations in Energetic Sources, Functional Compounds and Biotechnology, Engineering Materials, https://doi.org/10.1007/978-3-031-46545-1_2

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QDHOI are promising for upcoming generation commercial available cells which should desirable also be highly efficient, cost effective, non-toxic, non-degradable, have material availability, aesthetic design potential, large scale production and reciclability. The future holds practically unlimited applications in screens, greenhouses, roof tops, open areas, water surfaces, underwater communication, smart glasses, homes, factories, colorful/colorless windows, automobiles, aero/deep space travel, satellites, drones, robotics, telecommunications 5g, 6G, skylight applications, catalysis, energy storage, wearable electronics (e-skin), internet of things (IoT), building-integrated solar photovoltaic (BIPV), weather balloons, optical wireless communications (OWC), charging of laptops and mobile devices.

1 Introduction It is important to generate electricity from renewable, sustainable, environmental friendly energy sources keeping in mind costs, production, demands, supply and recycling. Plants leverage photochemical processes converting solar into chemical energy whereas the energy provided by the sun could also satisfy worldwide consumption once adequate, efficient and cost effefive tecnologies are dominated [1–11]. Fossil fuels play an important role in our society, fulfilling most of our daily requirements, but they are not unexhausible and require long formation periods. In 1893 the photovoltaic effect was reported leading to actual photovoltaic solar cells (PVScs) that can produce electricity from solar radiation taking into consideration the Schockly-Queisser efficiency limitations. Optimized large-scale manufacturing processes for the fabrication of cost effective efficient photovoltaic (PV) devices with novel technological properties could promote solar cell technologies to becoming the cheapest most used form of energy. In this chapter, we walk the readers through technological development generations of photovoltaic solar cells (PVScs) over the decades. We summarize the fundamental science of PSCs, Shockley-Queisser limit, generations, technological devices including (heterojunctions, multijunctions, tandem, multiple exciton generation, quantum dots, panels, arrays and power systems). Materials for PVScs including (inorganic semiconductors (Si, GaAs, CdTe, CIGS…), organic (small molecules, fullerenes, nonfullerenes, fused ring acceptors, non-fused ring electron acceptors, all polymer, polymer-small molecule acceptors), hybrid organic–inorganic (HOI), perovskite (Pe), Ruddelson-Popper phase (RP) Pe, Dion-Jacobson (DJ) phase Pe, dye synthetisized (DS), quantum dot (QD), colloidal QD (CoQD), QDDS, QDPe, QDHOI, core/yolk (shell), two dimensional nanolayers (2d-NL), graphene (G), graphene oxide (GO), reduced graphene (rGO), graphite, nanographite, carbon nano/quantum dot, graphene quantum dot (GQD), black/blue phosphorous, transition metal dichalcogenides, g-C3 N4 , low dimensional boron nitride (BN), Januslike nanocrystals, one-dimensional photonic crystal (1DPC), MXene, two dimensional van der Waals heterostructures (2d-vdWHs), borophene monolayer, nanowire, nanotubes, nanorods, nanofiber, tetrapods as well as semi-transparent, ultra-thin,

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ultra-light, flexible, 3d printable PVS cells/panels that work within technologicalbased devices. Artificial intelligence (AI) can help bridge the gap between costly/time comsuming resource trial-and-error approaches and multi-theory models in order to speculate about hypothetical PVScs devices inspiring design of appropriate models. Multiple exciton generation (MEG) is the phenomenon generating multiple excitons (electron–hole pairs) from a single high energy photon in some nanomaterials. Nanotechnological materials (NMat), such as two dimensional nanolayers and quantum dot materials, have important properties including ease of fabrication, costeffectiveness and tunable band gaps. AI, MEG and NMat applied to PVScs are also overviewed in this chapter. State of the art PVScs including QDDS, QDPe and QDHOI, which can be semi transparent, flexible, ultrathin, ultralight, printable, take advantage of full solar spectrum and also have additional desirable properties such as being worldwide available, cost effective, stable, non-degradable, recyclable, non-toxic with large scale production possibilities and aesthetic design are showing great promise for new upcoming generation PVScs/Panels. The future holds practically unlimited applications in screens, greenhouses, roof tops, open areas, smart glasses, homes, factories, colorful/colorless windows, automobiles, aero/deep space travel, satellites, drones, robotics, telecommunications 5g, 6G, skylight applications, catalysis, energy storage, wearable electronics (e-skin), internet of things (IoT), building-integrated solar photovoltaic (BIPV), weather balloons, optical wireless communications (OWC), charging of laptops and mobile devices.

2 Photovoltaic Solar Cells Becquerel is credited for discovering in 1839 the photovoltaic effect, i.e., operating principle of solar cells. The word photovoltaic originates from two words in greek, i.e. photo which means light and voltaic which means electric energy. When the semiconductor material surface is hit by sun light the electrons acquire energy, in the form of photons, becoming sufficientlly active to participate in conduction which results in electric currents generating electric energy. Over the decades, a number of semiconducting materials were investigated/used and numerous scientists, laboratories have participated in development of compounds that can generate electricity from the PV effect. Various technologies for utilizing the everlasting free solar radiation via solar cells/panels have been proposed. Actually, silicon (second most abundant element in the earth’s crust) is the most extensively used semiconductor material for making solar cells whereas the production and purification has become more affordable [1–11]. The essential solar generation of energy unit is a photovoltaic (PV) cell whereas sunlight is converted to electrical energy. A p-n junction device is a solar cell whereas p-type refers to charged holes (can be created by aceptor impurity atoms) and n-type

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refers to electrons (negatively charged and can be donated by impurities). In a pn junction electronic semiconductor there is an adsorption of photons in order to generate electron–hole pairs, i.e. charge carriers. Adsorption of photon with energy higher than the band gap of the doped semiconductor yields energy used to excite an electron from the valence band to the conduction level leaving a hole at the valence level. Additional, excess kinetic energy is given to the electron/hole, which is dissipated as heat in the semiconductor. The holes can flow through the p-region, away from the junction, in an external circuit, whereas electrons can cross the n-region through the circuit (before recombination with holes). William Schockley and Hans Queisser in 1961 calculated for a single pn junction solar cell the maximum theoretical efficiency, known as the detailed balance limit or Schockley-Queisser, limit by examining the amount of electrical energy extracted per incident photon which indicated maximum solar conversion efficiency of about 33.7% for bandgap of 1.4 eV, 6000 K blackbody radiation and AM 1.5 solar spectrum [11]. At room temperature the blackbody radiation cannot be captured by the cell and represents about 7% of available incoming energy. Since energy lost in cell is generally turned into heat, cell inefficiencies from sunlight increases temperature until equilibrium is attained. An upper limit to electron–hole production rate is placed by recombination (approximately 10% in silicon). At higher bangaps, with less photons, the current density decreases. About 19% will not produce power in silicon cells, for example, during AM 1.5 solar radiation since they will have energies