RESSALVA Atendendo solicitação do(a) autor(a), o texto completo deste documento será disponibilizado somente a partir de 27/09/2026. Henrique da Silva Gropelo Effect of thermal treatment on ZnO-derived zinc-metal-organic framework for detecting volatile organic compounds Dissertação apresentada como parte dos requisitos para obtenção do título de Mestre em Química, junto ao Programa de Pós-graduação em Química, do Institudo de Biociências, Letras e Ciências Exatas da Universidade Estadual Paulista “Júlio de Mesquita Filho”, Campus São José do Rio Preto. Financiadora: CAPES Orientador: Prof. Dr. Diogo Paschoalini Volanti São José do Rio Preto 2024 Sistema de geração automática de fichas catalográficas da Unesp. Dados fornecidos pelo autor(a). G876e Gropelo, Henrique da Silva Effect of thermal treatment on ZnO-derived zinc-metal-organic framework for detecting volatile organic compounds / Henrique da Silva Gropelo. -- São José do Rio Preto, 2024 47 f. : tabs., fotos Dissertação (mestrado) - Universidade Estadual Paulista (UNESP), Instituto de Biociências Letras e Ciências Exatas, São José do Rio Preto Orientador: Diogo Paschoalini Volanti 1. Semiconductors. 2. Metal-organic framework. 3. Zinc oxide. 4. Sensors. 5. Microbial volatile organic compounds. I. Título. ACKNOWLEDGEMENTS First, I would like to thank my mother, Rosi, and my entire family for always supporting me for all the love, affection, help, and dedication throughout my career. I would like to thank my cousin and brother, Bruno Ricardo, for always inspiring me to do my best, to seek more knowledge and academic development, and for all the teachings and help he has given me over the years. I would especially like to thank my girlfriend, Maria Clara, for always being by my side and helping me through difficult times, for always inspiring me to do my best and never letting me give up, and for all the love, affection, patience, and teachings throughout our journey together. I would also like to thank her and her entire family for all their love, care, and affection. To my lab colleagues, especially Reinaldo, Gustavo, and Vitor, for all their teachings and help during the development of this research. I would like to thank my advisor, Diogo Volanti, for the opportunity to join LabMatSus and for his guidance and support throughout this research. I thank IBILCE for all the opportunities, from undergraduate to graduate studies. I would also like to thank the laboratories LSQA/IBILCE-UNESP for providing the XRD and FTIR techniques, LabCat DEQ/UFSCar for the TGA analysis, LCE DEMa/UFSCar for the TEM analysis, LMA/IQ-UNESP for FESEM and EDX, and LNNanano – CNPEM for the XPS analyzes (proposal – 20241266) and LNLS – SIRIUS for the XAS analyzes (proposal – 20232482). I would like to especially thank the Pro-Rector for Research regarding the CIC Award "LET THE MASTER'S DEGREE COME!" (PROPe Unesp Notice No. 01/2022) for the CAPES scholarship, encouraging research and academic development. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. RESUMO Este trabalho apresenta a aplicação de ZnO, um óxido metálico semicondutor do tipo n, derivado de estrutura metal-orgânica (MOF), para detecção de compostos orgânicos voláteis microbianos (MVOCs). A detecção rápida, seletiva e em baixos limites de detecção é um dos principais desafios relatados. Além disso, estudos sobre a influência dos tamanhos de cristalitos do óxido metálico no desempenho do sensor ainda são escassos. A proposta e foco desta pesquisa consistem na aplicação de ZnO com diferentes tamanhos de cristalitos no desempenho como sensor de MVOCs. O precursor do ZnO (MOF-5) foi preparado utilizando o método solvotérmico assistido por micro-ondas, empregando o sal metálico 𝑍𝑛(𝑁𝑂3)2. 6𝐻2𝑂 e ligante orgânico ácido tereftálico em dimetilfomamida (DMF). O ZnO, aplicado como sensor, foi sintetizado pela degradação térmica (400 °C a 800 °C) da MOF-5, resultando em ZnO com tamanhos variados de nanopartículas: 17,8 nm a 450 °C (ZnO-450), 26,8 nm a 600 °C (ZnO- 600) e 34,3 nm a 800 °C (ZnO-800). As caracterizações eletrônicas e estruturais evidenciam a formação de ZnO puros e fases cristalinas desejadas. Os sensores foram testados para 100 ppm dos MVOCs: acetona, 2-butanona, m-xileno, tolueno, benzeno e 1-Pentanol, em temperaturas variadas de 200 °C a 450 °C. Todos os sensores apresentaram boa detecção dos MVOCs 1- pentanol e 2-butanona a 400 °C, com destaque para o sensor ZnO-450, que exibiu a maior resposta ao MVOC 1-pentanol, atingindo um valor de resposta de 2680,0. Entretanto, observou- se uma alta sensibilidade e seletividade no sensor ZnO-600, com uma resposta de 2205,0 para 1-pentanol na mesma temperatura de operação, sendo que sua seletividade entre os MVOCs 1- pentanol e 2-butanona foi maior quando comparado ao sensor com tamanho de cristalito de 17,8 nm. Os mesmos parâmetros de seletividade do sensor ZnO-600 foram observados para o sensor ZnO-800, com tamanho de cristalito de 34,3 nm, embora os valores de resposta para os MVOCs 1-pentanol e 2-butanona tenham sido inferiores, 232,0 e 100,01, respectivamente. Portanto, demonstramos que o tamanho das nanoparticulas de ZnO influência diretamente a resposta e o desempenho do sensor, sendo mais seletivo para 1-pentanol a 400 °C o sensor de ZnO calcinado a 600 °C, com tamanho de cristalito de 26,8 nm. Destaca-se também o bom desempenho desse sensor na presença de uma atmosfera úmida e em diferentes faixas de umidade relativa controlada. Palavras–chave: Semicondurores tipo n. MOF-5. Óxido de zinco. Sensor de gás. 1-Pentanol. ABSTRACT This work presents the application of ZnO, an n-type semiconductor metal oxide derived from a metal-organic framework (MOF), for the detection of microbial volatile organic compounds (MVOCs). Rapid, selective detection with low limits of detection is one of the main reported challenges. Furthermore, studies on the influence of metal oxide crystallite sizes on sensor performance are still scarce. The proposal and focus of this research are the application of ZnO with different crystallite sizes to evaluate its performance as an MVOC sensor. The ZnO precursor (MOF-5) was prepared using a microwave-assisted solvothermal method, employing the metal salt Zn(NO₃)₂·6H₂O and the organic ligand terephthalic acid in dimethylformamide (DMF). ZnO, applied as a sensor, was synthesized by thermal degradation (400 °C to 800 °C) of MOF-5, resulting in ZnO with varied nanoparticle sizes: 17.8 nm at 450 °C (ZnO-450), 26.8 nm at 600 °C (ZnO-600), and 34.3 nm at 800 °C (ZnO-800). Electronic characterizations and structural analyses confirm the formation of pure ZnO and the desired crystalline phases. The sensors were tested for 100 ppm of the MVOCs: acetone, 2-butanone, m-xylene, toluene, benzene, and 1-pentanol, at varying temperatures from 200 °C to 450 °C. All sensors showed good detection of the MVOCs 1-pentanol and 2-butanone at 400 °C, with particular emphasis on the ZnO-450 sensor, which exhibited the highest response to the MVOC 1-pentanol, reaching a response value of 2680.0. However, high sensitivity and selectivity were observed in the ZnO-600 sensor, with a response of 2205.0 for 1-pentanol at the same operating temperature, and its selectivity between the MVOCs 1-pentanol and 2-butanone was higher compared to the sensor with a crystallite size of 17.8 nm. The same selectivity parameters of the ZnO-600 sensor were observed for the ZnO-800 sensor, with a crystallite size of 34.3 nm, although the response values for the MVOCs 1-pentanol and 2-butanone were lower, at 232.0 and 100.01, respectively. Therefore, we demonstrate that the size of the ZnO nanoparticles directly influences the response and performance of the sensor, with the ZnO sensor calcined at 600 °C and with a crystallite size of 26.8 nm being more selective for 1-pentanol at 400 °C. The good performance of this sensor in the presence of a humid atmosphere and across different ranges of controlled relative humidity is also noteworthy. Keywords: n-type semiconductors. MOF-5. Zinc oxide. Gas sensor. 1-Pentanol. LIST OF ILLUSTRATIONS Figura 1 – Overview of volatile organic compounds and their interactions. 15 Figura 2 – N-type detection mechanism for 1-pentanol gas. 17 Figura 3 – Synthesis process of MOF-5 and ZnO nanoparticles. 23 Figura 4 – Diagram of the sensor measurement system. Preparation of ZnO sensors a) intergited Au electrodes, b) deposition on ZnO in electrod. 25 Figura 5 – (a) TG curve of MOF-5, (b) XRD pattern, (c) FTIR spectra of MOF-5, ZnO-450, ZnO-600, ZnO-800. Isotherms by nitrogen adsorption and desorption for ZnO-450 (d), ZnO-600 (e) and ZnO-800 (f). 26 Figura 6 – FESEM images of MOF-5 (a) and ZnO-450 (b), ZnO-600 (c) and ZnO-800 (d). 29 Figura 7 – a,b) Transmission Microscopy images of ZnO nanoparticles calcined at 600 °C (ZnO-600) c) HRTEM d) EDS elemental mapping e) SAED images of porous ZnO-600 f) Illustration of ZnO nanoparticles. 30 Figura 8 – (a) XPS survey scan spectra of ZnO-450, ZnO-600, and ZnO-800. High- resolution XPS spectra from O 1s of the ZnO-450 (b), ZnO-600 (c), ZnO-800 (d) and (e) Zn 2p ZnO-450, (f) Zn 2p ZnO-600 and (g) Zn 2p ZnO-800. 31 Figura 9 – XAS spectra in TEY to O (a) and Zn (b) K-edge of ZnO-450, ZnO-600 and ZnO-800. 32 Figura 10 – Selectivity measurements for different MVOCs (100 ppm) by ZnO-400 (a), ZnO-600 (b), and ZnO-800 (c) sensors under various operating temperatures and dry atmosphere. Response and recovery times to 100 ppm 1-pentanol at 400 °C of ZnO-400 (d), ZnO-600 (e), and ZnO-800 (f) sensors. Performance tests of the ZnO- 600 sensor for different concentrations of 1-pentanol at 400 °C in a dry atmosphere (g) and repeatability of the sensor at 2 ppm (h). Radar plot for 1-pentanol selectivity ratio (i). 35 Figura 11 – Responses of the ZnO-600 sensor at 400 °C to 2 ppm 1-Pentanol in the dry and humid atmosphere (a), b) detection limit and c) stability of the ZnO-600 sensor. 36 Figura 12 – Detection mechanism of ZnO sensor for 2 ppm 1-pentanol in dry atmosphere at 400°C. 39 LIST OF TABLES Tabela 1 – Comparison of surface area, dimensions, and pore volume of the materials synthesized in this study. 28 Tabela 2 – Comparison of MVOCs detection performance in the dry atmosphere of different sensors was described in the literature 37 ABREVIATIONS AND ACRONYMS LIST BET Brunauer-Emmett-Teller EDX Energy-dispersive X-ray FESEM Field emission scanning electron microscopy FTIR Fourier transform infrared spectroscopy HRTEM High-resolution transmission electron microscopy MOF Metal-organic framework MVOC Microbial volatile organic compound RH Relative humidity SMO Semiconducting metal oxide TEM Transmission eléctron microscope TEY Total eléctron-yield TFY Total fluorescence-yield TGA Thermogravimetric analyses XAS X-ray absorption spectroscopy XPS X-ray photoelectron spectroscopy XRD X-ray Diffraction SYMBOLS LIST Å Angstrom °C Celsius degree cm Centimeter nm Nanometer cm3/g Cubic centimetre per gram eV Electron volt g Gram h Hour keV Kilo eléctron volt kV Kilovolt mA Milliampère mg Milligram mL Milliliter mmol Millimol min Minute ppm Parts per million s Second m2 g-1 Square meter per gram SUMMARY 1 INTRODUCTION AND BIBLIOGRAPHIC REVIEW 13 1.1 Microbial volatile organic compounds (MVOCs) 13 1.2 Semiconductor metal oxides based on ZnO for MVOC detection 15 1.3 Metal-organic framework-derived SMO synthesis method 18 2 EFFECT OF THERMAL TREATMENT ON ZnO-DERIVED ZINC- METAL-ORGANIC FRAMEWORK FOR DETECTING 1-PENTANOL 20 2.1 Introduction 21 2.2 Methods 2.2.1 Chemicals and Materials 2.2.2 Synthesis of MOF-5 and nanoparticles of ZnO 2.2.3 Characterizations 2.2.4 Sensors measurements and MVOC fabrication 2.3 Results and discussion 2.3.1 Characterization of MOF-5 and ZnO nanoparticles 2.3.2 MVOCs sensing measurements 2.3.3 1-Pentanol sensing mechanism 2.4 Conclusion 22 22 22 23 24 25 25 33 37 39 Acknowledgments 40 3 CONCLUSION AND NEXT CHALLENGES 41 REFERÊNCIAS 42 13 1 INTRODUCTION AND BIBLIOGRAPHIC REVIEW The development of conductometric sensors based on semiconductor metal oxides (SMOs) has gained prominence in the detection of microbial volatile organic compounds (MVOCs) (BARSAN; KOZIEJ; WEIMAR, 2007; BARSAN; WEIMAR, 2020) compared to other detection methods, such as optical and mechanical ones (SOHRABI et al., 2023), due to their great multifunctionality, morphological diversification, physical, chemical and thermal stability, in addition to low costs (CHATTERJEE; MITRA; MUKHOPADHYAY, 1999; WANG et al., 2020; WAN et al., 2004). The importance of detecting different chemical classes of these compounds, produced by microorganisms, arises from several factors that directly impact society (ANAND; PHILIP; MEHENDALE, 2014; KAMPA; CASTANAS, 2008; KORPI; JÄRNBERG; PASANEN, 2009; PASANEN et al., 1998; SCHULZ; DICKSCHAT, 2007). Among these factors are food spoilage (WANG et al., 2016) and the danger to human health caused by pathogenic microorganisms (PASQUARELLA; PITZURRA; SAVINO, 2000; SCHÜTZE et al., 2017). Furthermore, there are volatile organic compounds exhaled through respiration that are directly associated with diseases such as cancer and can act as biomarkers, aiding in the diagnosis of potentially undetectable diseases (MACHADO et al., 2015; SCHMIDT; PODMORE, 2015; SUN; SHAO; WANG, 2016). In this context, this research aimed to synthesize and apply ZnO-based SMO sensors for detecting MVOCs. SMOs are materials with unique and highly versatile electrical characteristics, mainly when derived from metal-organic frameworks (MOFs) (WANG et al., 2020), ensuring high surface area, porosity, absorptivity, and crystallinity (KUMAR; MASRAM, 2021). These properties have great potential for application in toxic gas detection (SOHRABI et al., 2023). The sensor properties are directly linked to their morphology, particularly the crystallite size of the material (REN et al., 2022), which directly influences the material's active sites and gas adsorption capacity (XU et al., 2000), thereby altering the sensor performance. 1.1 Microbial volatile organic compounds (MVOCs) Identifying and controlling the emission of atmospheric pollutants known as volatile organic compounds (VOCs) is of great importance due to their impact on society (HAO et al., 2024). VOCs correspond to organic compounds with boiling points below 250 °C and high vapor pressures, evaporating quickly (ANAND; PHILIP; MEHENDALE, 2014; HE et al., 2019). They are responsible for the reduction of air quality (KAMPA; CASTANAS, 2008), and 15 Figure 1 – Overview of volatile organic compounds and their interactions. Source: adaptation from literature (KAMPA; CASTANAS, 2008; SCHÜTZE et al., 2017; SUN; SHAO; WANG, 2016). Furthermore, some MVOCs are produced by specific microorganisms, which, when exhaled by the respiratory system, can be directly associated with diseases, acting as biomarkers and aiding in the diagnosis of potentially undetectable diseases (DUFFY; MORRIN, 2019; MACHADO et al., 2015; SCHMIDT; PODMORE, 2015). Currently, conventional methods cannot meet monitoring and safety requirements as they require expensive and time-consuming processes to identify microorganisms and MVOCs (ZHU et al., 2019), such as the use of gas chromatography coupled with mass spectrometry, as well as chemiluminescent and fluorescent sensing techniques. Therefore, the application of semiconductor metal oxide sensors can address these issues in a simple and cost-effective way, enabling the rapid, practical, efficient, and selective detection of MVOCs, while also facilitating the integration of information that can assist in disease diagnosis and food safety risk assessment 1.2 Semiconductor metal oxides based on ZnO for MVOC detection Semiconductor metal oxides (SMOs) comprise a class of materials with excellent electrical characteristics and are widely used in several areas, such as catalysis and photocatalysis (DJURIŠIĆ; LEUNG; CHING NG, 2014; ZHANG; LIN, 2014), supercapacitors, energy storage, and conversion (WU et al., 2011), and primarily as sensors for detecting toxic gases (KRISHNA et al., 2022; SOHRABI et al., 2023; WANG et al., 2020). SMOs are classified as n-type or p-type according to the type of receptor and conduction mechanisms (KIM; LEE, 2014). N-type and p-type semiconduction arise from extrinsic defects. 41 3 CONCLUSION AND NEXT CHALLENGES This research aimed to develop ZnO sensors for the detection of MVOCs under various operating conditions. In line with this objective, Chapter 2 provides a review of key topics, specifically MVOCs and conductometric sensors based on semiconductor metal oxides (SMOs). Detecting MVOCs is crucial due to the environmental and social problems caused by various classes of bacteria and fungi. The rapid and selective identification of these compounds, using low-cost materials, drives the search for new alternatives. The synthesized ZnO proved to be an excellent material for MVOC detection, especially for 1-pentanol, when the crystallite size of the nanoparticles was modified. Chapter 3 describes the fabrication of ZnO through the thermal treatment of a MOF-5 precursor, synthesized via a microwave-assisted solvothermal method. Varying the crystallite size enhanced sensor performance. At the optimal operating temperature, ZnO with intermediate crystallite size demonstrated increased selectivity, improved detection of 1-pentanol, and the shortest response time among all the sensors studied. Future challenges include better characterization of the synthesized material using Transmission Electron Microscopy (TEM) to obtain more detailed structural information, as well as a more in-depth investigation of the electronic and surface properties of ZnO through X-ray absorption spectroscopy and X-ray photoelectron spectroscopy analyses. These analyses will provide clearer insight into the detection mechanism. Furthermore, this study aims to support future research into the development of simple ZnO sensors derived from MOF-5, while demonstrating the importance and influence of nanoparticle size on sensor performance, whether for 1-pentanol or other MVOCs produced by specific bacteria and fungi. This will contribute to the development and expansion of the MVOC database. Improving selectivity and sensor applications under real-world temperature and humidity conditions remains a significant challenge in this field. 42 REFERENCES ANAND, S. S.; PHILIP, B. K.; MEHENDALE, H. M. Volatile Organic Compounds. Em: Encyclopedia of Toxicology: Third Edition. [s.l.] Elsevier, 2014. p. 967–970. ARAÚJO, E. A. et al. Synthesis, growth mechanism, optical properties and catalytic activity of ZnO microcrystals obtained via hydrothermal processing. RSC Advances, v. 7, n. 39, p. 24263–24281, 2017. BARSAN, N.; KOZIEJ, D.; WEIMAR, U. Metal oxide-based gas sensor research: How to? Sensors and Actuators, B: Chemical, v. 121, n. 1, p. 18–35, 30 jan. 2007. BARSAN, N.; WEIMAR, U. Conduction Model of Metal Oxide Gas SensorsJournal of Electroceramics. [s.l: s.n.]. BARSAN, N.; WEIMAR, U. 7.3.3 Fundamentals of Metal Oxide Gas Sensors. AMA Service GmbH, 18 dez. 2020. CHATTERJEE, A. P.; MITRA, P.; MUKHOPADHYAY, A. K. P1: FJL/FIX P2: FJS/LMQ/FIA P3: FJM/FGD Chemically deposited zinc oxide thin film gas sensor. [s.l: s.n.]. CHEN, T. et al. Correlation between electronic structure and magnetic properties of Fe-doped ZnO films. Journal of Applied Physics, v. 111, n. 12, 15 jun. 2012. DA TRINDADE, L. G. et al. Influence of ionic liquid on the photoelectrochemical properties of ZnO particles. Ceramics International, v. 44, n. 9, p. 10393–10401, 15 jun. 2018. DE PERES, M. L. et al. Zinc oxide nanoparticles from microwave-assisted solvothermal process: Photocatalytic performance and use for wood protection against xylophagous fungus. Nanomaterials and Nanotechnology, v. 9, 2019. DE SÁ, B. S. et al. Microwave-assisted solvothermal synthesis of In-MIL-68 derived hollow In2O3 microrods for enhanced 1-pentanol sensing performance. Materials Today Communications, v. 37, 1 dez. 2023. DJURIŠIĆ, A. B.; LEUNG, Y. H.; CHING NG, A. M. Strategies for improving the efficiency of semiconductor metal oxide photocatalysis. Materials HorizonsRoyal Society of Chemistry, , 1 jul. 2014. DONG, C.-L. Soft-x-ray spectroscopy probes nanomaterial-based devices. SPIE Newsroom, 2007. DUFFY, E.; MORRIN, A. Endogenous and microbial volatile organic compounds in cutaneous health and disease. TrAC - Trends in Analytical ChemistryElsevier B.V., , 1 fev. 2019. EWALD, C. et al. Role of potassium loading in ZnO-based gas sensors under NO2 exposure – Operando diffuse reflectance infrared Fourier transform spectroscopic study. Sensors and Actuators B: Chemical, v. 393, p. 134321, 15 out. 2023. 43 FENNELL, J. F. et al. Nanodrähte in Chemo‐ und Biosensoren: aktueller Stand und Fahrplan für die Zukunft. Angewandte Chemie, v. 128, n. 4, p. 1286–1302, 22 jan. 2016. FRANKE, M. E.; KOPLIN, T. J.; SIMON, U. Metal and metal oxide nanoparticles in chemiresistors: Does the nanoscale matter? Small, jan. 2006. GE, M. et al. Controllable synthesis of hierarchical assembled porous ZnO microspheres for acetone gas sensor. Sensors and Actuators, B: Chemical, v. 220, p. 356–361, 10 jul. 2015. GUO, L. et al. Gas sensor based on MOFs-derived Au-loaded SnO2 nanosheets for enhanced acetone detection. Journal of Alloys and Compounds, v. 906, 15 jun. 2022. HAO, R. et al. Emission characteristics, environmental impact, and health risk assessment of volatile organic compounds (VOCs) during manicure processes. Science of the Total Environment, v. 906, 1 jan. 2024. HE, C. et al. Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources. Chemical ReviewsAmerican Chemical Society, , 10 abr. 2019. HERNÁNDEZ-MACEDO, M. L. et al. Gases and volatile compounds associated with microorganisms in blown pack spoilage of Brazilian vacuumpacked beef. Letters in Applied Microbiology, v. 55, n. 6, p. 467–475, 2012. HE, Y. et al. ZIF-8 derived ZnWO4 nanocrystals: Calcination temperature induced evolution of composition and microstructures, and their electrochemical performances as anode for lithium-ion batteries. Electrochimica Acta, v. 367, 20 jan. 2021. JAISWAL, J.; SINGH, P.; CHANDRA, R. Low-temperature highly selective and sensitive NO2 gas sensors using CdTe-functionalized ZnO filled porous Si hybrid hierarchical nanostructured thin films. Sensors and Actuators, B: Chemical, v. 327, 15 jan. 2021. JEONG, S. Y.; KIM, J. S.; LEE, J. H. Rational Design of Semiconductor-Based Chemiresistors and their Libraries for Next-Generation Artificial Olfaction. Advanced MaterialsWiley-VCH Verlag, , 1 dez. 2020. JING, Z.; ZHAN, J. Fabrication and gas-sensing properties of porous ZnO nanoplates. Advanced Materials, v. 20, n. 23, p. 4547–4551, 2 dez. 2008. KAMPA, M.; CASTANAS, E. Human health effects of air pollution. Environmental Pollution, jan. 2008. KAZEMIAN, M. et al. X-ray imaging and micro-spectroscopy unravel the role of zincate and zinc oxide in the cycling of zinc anodes in mildly acidic aqueous electrolytes. Journal of Power Sources, v. 524, 15 mar. 2022. KHATIB, M.; HAICK, H. Sensors for Volatile Organic Compounds. ACS NanoAmerican Chemical Society, , 24 maio 2022. 44 KIM, H. J.; LEE, J. H. Highly sensitive and selective gas sensors using p-type oxide semiconductors: Overview. Sensors and Actuators, B: Chemical, 1 mar. 2014. KIM, I. D.; ROTHSCHILD, A.; TULLER, H. L. Advances and new directions in gas-sensing devices. Acta Materialia, v. 61, n. 3, p. 974–1000, fev. 2013. KORPI, A.; JÄRNBERG, J.; PASANEN, A. L. Microbial volatile organic compounds. Critical Reviews in Toxicology, fev. 2009. KRISHNA, K. G. et al. Nanostructured metal oxide semiconductor-based gas sensors: A comprehensive review. Sensors and Actuators A: PhysicalElsevier B.V., , 1 jul. 2022. KUMAR, G.; MASRAM, D. T. Sustainable Synthesis of MOF-5@GO Nanocomposites for Efficient Removal of Rhodamine B from Water. ACS Omega, v. 6, n. 14, p. 9587–9599, 13 abr. 2021. LANGFORD, J. I.; WILSON, A. J. C. Seherrer after Sixty Years: A Survey and Some New Results in the Determination of Crystallite SizeJ. Appl. Cryst. [s.l: s.n.]. LEE, I. et al. Hollow Metal-Organic Framework Microparticles Assembled via a Self- Templated Formation Mechanism. Crystal Growth and Design, v. 15, n. 11, p. 5169–5173, 29 set. 2015. LEE, J. et al. Precise control of surface oxygen vacancies in ZnO nanoparticles for extremely high acetone sensing response. Journal of Advanced Ceramics, v. 11, n. 5, p. 769–783, 1 maio 2022. LI, P. Z.; ARANISHI, K.; XU, Q. ZIF-8 immobilized nickel nanoparticles: Highly effective catalysts for hydrogen generation from hydrolysis of ammonia borane. Chemical Communications, v. 48, n. 26, p. 3173–3175, 29 fev. 2012. LÜ, Y. et al. MOF-templated synthesis of porous Co3O4 concave nanocubes with high specific surface area and their gas sensing properties. ACS Applied Materials and Interfaces, v. 6, n. 6, p. 4186–4195, 26 mar. 2014. MACHADO, M. M. et al. Construção de um reator de plasma descarga corona para eliminação de compostos orgânicos voláteis. Quimica Nova, v. 38, n. 1, p. 128–131, 1 jan. 2015. MANDAYO, G. G. et al. Strategies to enhance the carbon monoxide sensitivity of tin oxide thin films. Sensors and Actuators, B: Chemical. Anais...15 out. 2003. MATSUNAGA, N. et al. Formulation of gas diffusion dynamics for thin film semiconductor gas sensor based on simple reaction-diffusion equation. Sensors and Actuators, B: Chemical, v. 96, n. 1–2, p. 226–233, 15 nov. 2003. Micromachined metal oxide gas sensors opportunities to improve sensor performance (Simon, Barsan, 2001). [s.d.]. 45 MITTAL, A.; ROY, I.; GANDHI, S. Drug Delivery Applications of Metal-Organic Frameworks (MOFs). [s.l: s.n.]. Disponível em: . MOKOENA, T. P.; SWART, H. C.; MOTAUNG, D. E. A review on recent progress of p- type nickel oxide based gas sensors: Future perspectives. Journal of Alloys and Compounds, v. 805, p. 267–294, 15 out. 2019. OLIVEIRA, T. N. T. et al. Improved triethylamine sensing properties by designing an In2O3/ZnO heterojunction. Sensors and Actuators Reports, v. 3, 1 nov. 2021. OPREA, A. et al. Basics of semiconducting metal oxide-based gas sensors. Em: Gas Sensors Based on Conducting Metal Oxides: Basic Understanding, Technology and Applications. [s.l.] Elsevier, 2018. p. 61–165. PASANEN, A.-L. et al. CRITICAL ASPECTS ON THE SIGNIFICANCE OF MICROBIAL VOLATILE METABOLITES AS INDOOR AIR POLLUTANTSEnvironment International. [s.l: s.n.]. PASQUARELLA, C.; PITZURRA, O.; SAVINO, A. The index of microbial air contamination. Journal of Hospital InfectionW.B. Saunders Ltd, , 2000. PERFECTO, T. M.; ZITO, C. A.; VOLANTI, D. P. Effect of NiS nanosheets on the butanone sensing performance of ZnO hollow spheres under humidity conditions. Sensors and Actuators, B: Chemical, v. 334, 1 maio 2021. REN, X. et al. Conductometric NO2 gas sensors based on MOF-derived porous ZnO nanoparticles. Sensors and Actuators B: Chemical, v. 357, 15 abr. 2022. ROSO, S. et al. Synthesis of ZnO nanowires and impacts of their orientation and defects on their gas sensing properties. Sensors and Actuators, B: Chemical, v. 230, p. 109–114, 1 jul. 2016. SALUNKHE, R. R.; KANETI, Y. V.; YAMAUCHI, Y. Metal-Organic Framework- Derived Nanoporous Metal Oxides toward Supercapacitor Applications: Progress and Prospects. ACS NanoAmerican Chemical Society, , 27 jun. 2017. SANTOS, G. S. M. et al. MOF-derived Co3O4-ZnO heterostructure for 3-methyl-1-butanol detection. Sensors and Actuators B: Chemical, v. 408, 1 jun. 2024. SCHMIDT, K.; PODMORE, I. Current Challenges in Volatile Organic Compounds Analysis as Potential Biomarkers of Cancer. Journal of Biomarkers, v. 2015, p. 1–16, 30 mar. 2015. SCHULZ, S.; DICKSCHAT, J. S. Bacterial volatiles: The smell of small organisms. Natural Product Reports, 2007. SCHÜTZE, A. et al. Highly sensitive and selective VOC sensor systems based on semiconductor gas sensors: How to? Environments - MDPI, v. 4, n. 1, p. 1–13, 1 mar. 2017. 46 SOHRABI, H. et al. Metal-organic frameworks (MOF)-based sensors for detection of toxic gases: A review of current status and future prospects. Materials Chemistry and Physics, v. 299, 15 abr. 2023. SUN, X.; SHAO, K.; WANG, T. Detection of volatile organic compounds (VOCs) from exhaled breath as noninvasive methods for cancer diagnosis Young Investigators in Analytical and Bioanalytical Science. Analytical and Bioanalytical Chemistry, v. 408, n. 11, p. 2759– 2780, 1 abr. 2016. Synthesis and characterization of a new hybrid material (MOF5)(BENNABI; BELBACHIR, 2017). [s.d.]. THOMMES, M. et al. Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure and Applied Chemistry, v. 87, n. 9–10, p. 1051–1069, 1 out. 2015. THORN, R. M. S.; GREENMAN, J. Microbial volatile compounds in health and disease conditions. Journal of Breath Research, jun. 2012. TURGUT, E. et al. Oxygen partial pressure effects on the RF sputtered p-type NiO hydrogen gas sensors. Applied Surface Science, v. 435, p. 880–885, 30 mar. 2018. WANG, Y. et al. Microbial volatile organic compounds and their application in microorganism identification in foodstuff. TrAC - Trends in Analytical ChemistryElsevier B.V., , 1 abr. 2016. WANG, Y. et al. Microwave hydrothermally synthesized metal-organic framework-5 derived C-doped ZnO with enhanced photocatalytic degradation of Rhodamine B. Langmuir, v. 36, n. 33, p. 9658–9667, 25 ago. 2020. WAN, Q. et al. Fabrication and ethanol sensing characteristics of ZnO nanowire gas sensors. Applied Physics Letters, v. 84, n. 18, p. 3654–3656, 3 maio 2004. WEN, W.; WU, J. M.; WANG, Y. DE. Large-size porous ZnO flakes with superior gas- sensing performance. Applied Physics Letters, v. 100, n. 26, 25 jun. 2012. WILLIAMS, D. E. Semiconducting oxides as gas-sensitive resistorsSensors and Actuators B. [s.l: s.n.]. WOO, H. S. et al. Co-doped branched ZnO nanowires for ultraselective and sensitive detection of xylene. ACS Applied Materials and Interfaces, v. 6, n. 24, p. 22553–22560, 24 dez. 2014. WU, W. et al. Controlled synthesis of monodisperse sub-100 nm hollow SnO2 nanospheres: A template-and surfactant-free solution-phase route, the growth mechanism, optical properties, and application as a photocatalyst. Chemistry - A European Journal, v. 17, n. 35, p. 9708–9719, 22 ago. 2011. XU, C. et al. Grain size effects on gas sensitivity of porous Sn02-based elementsSensors and Actuators B. [s.l: s.n.]. 47 XU, H. et al. A novel method for improving the performance of ZnO gas sensors. Sensors and Actuators, B: Chemical, v. 114, n. 1, p. 301–307, 30 mar. 2006. XU, J. et al. Grain size control and gas sensing properties of ZnO gas sensorSensors and Actuators B. [s.l: s.n.]. Disponível em: . ZAKI, S. E. et al. Role of oxygen vacancies in vanadium oxide and oxygen functional groups in graphene oxide for room temperature CO2 gas sensors. Sensors and Actuators, A: Physical, v. 294, p. 17–24, 1 ago. 2019. ZHANG, D. et al. Room-temperature high-performance acetone gas sensor based on hydrothermal synthesized SnO2-reduced graphene oxide hybrid composite. RSC Advances, v. 5, n. 4, p. 3016–3022, 2015. ZHANG, S. B.; WEI, S. H.; ZUNGER, A. Intrinsic n-type versus p-type doping asymmetry and the defect physics of ZnO. Physical Review B - Condensed Matter and Materials Physics, v. 63, n. 7, 31 jan. 2001. ZHANG, T.; LIN, W. Metal-organic frameworks for artificial photosynthesis and photocatalysis. Chemical Society ReviewsRoyal Society of Chemistry, , 21 ago. 2014. ZHANG, X. et al. ZIF-8 derived hierarchical hollow ZnO nanocages with quantum dots for sensitive ethanol gas detection. Sensors and Actuators, B: Chemical, v. 289, p. 144–152, 15 jun. 2019. ZHAO, J. et al. Microwave Hydrothermal Synthesis of In 2 O 3 -ZnO Nanocomposites and Their Enhanced Photoelectrochemical Properties . Journal of The Electrochemical Society, v. 166, n. 5, p. H3074–H3083, 2019. ZHU, Z. et al. Multichannel pathway-enriched mesoporous NiO nanocuboids for the highly sensitive and selective detection of 3-hydroxy-2-butanone biomarkers. Journal of Materials Chemistry A, v. 7, n. 17, p. 10456–10463, 2019. ZITO, C. A. et al. Bicone-like ZnO structure as high-performance butanone sensor. Materials Letters, v. 223, p. 142–145, 15 jul. 2018.