{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,11]],"date-time":"2026-01-11T03:09:24Z","timestamp":1768100964884,"version":"3.49.0"},"reference-count":42,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,20]],"date-time":"2022-08-20T00:00:00Z","timestamp":1660953600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100014735","name":"JAPAN KEIRIN AUTORACE ASSOCIATION (JKA)","doi-asserted-by":"publisher","award":["2020M-206"],"award-info":[{"award-number":["2020M-206"]}],"id":[{"id":"10.13039\/501100014735","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100014735","name":"JAPAN KEIRIN AUTORACE ASSOCIATION (JKA)","doi-asserted-by":"publisher","award":["20KK0110"],"award-info":[{"award-number":["20KK0110"]}],"id":[{"id":"10.13039\/501100014735","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Promotion of Joint International Research (Fostering Joint International Research(B))","doi-asserted-by":"publisher","award":["2020M-206"],"award-info":[{"award-number":["2020M-206"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Promotion of Joint International Research (Fostering Joint International Research(B))","doi-asserted-by":"publisher","award":["20KK0110"],"award-info":[{"award-number":["20KK0110"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Understanding the surface chemistry of target gases on sensing materials is essential for designing high-performance gas sensors. Here, we report the effect of Pt-loading on the sensing of volatile organic compounds (VOCs) with ZnO gas sensors, demonstrated by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Pt-loaded ZnO nanocrystals (NCs) of 13~22 nm are synthesized using the hot soap method. The synthesized powder is deposited on an alumina substrate by screen-printing to form a particulate gas sensing film. The 0.1 wt% Pt-loaded ZnO NC sensor shows the highest sensor response to acetone and ethanol at 350 \u00b0C, while the responses to CO and H2 are small and exhibit good selectivity to VOCs. The gas sensing mechanism of ethanol with Pt-ZnO NCs was studied by in situ DRIFT spectroscopy combined with online FT-IR gas analysis. The results show that ethanol reacts with small Pt-loaded ZnO to produce intermediate species such as acetaldehyde, acetate, and carbonate, which generates a high sensor response to ethanol in air.<\/jats:p>","DOI":"10.3390\/s22166277","type":"journal-article","created":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T01:56:40Z","timestamp":1661133400000},"page":"6277","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Study on Sensing Mechanism of Volatile Organic Compounds Using Pt-Loaded ZnO Nanocrystals"],"prefix":"10.3390","volume":"22","author":[{"given":"Takeshi","family":"Shinkai","sequence":"first","affiliation":[{"name":"Department of Material Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan"}]},{"given":"Keigo","family":"Masumoto","sequence":"additional","affiliation":[{"name":"Department of Material Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan"}]},{"given":"Masaru","family":"Iwai","sequence":"additional","affiliation":[{"name":"Department of Material Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan"}]},{"given":"Yusuke","family":"Inomata","sequence":"additional","affiliation":[{"name":"Division of Materials Science, Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9357-9557","authenticated-orcid":false,"given":"Tetsuya","family":"Kida","sequence":"additional","affiliation":[{"name":"Division of Materials Science, Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan"},{"name":"Institute of Industrial Nanomaterials, Kumamoto University, Kumamoto 860-8555, Japan"},{"name":"International Research Organization for Advanced Science and Technology (IROAST), Kumamoto University, Kumamoto 860-8555, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1502","DOI":"10.1021\/ac60191a001","article-title":"A New Detector for Gaseous Components Using Semiconductive Thin Films","volume":"34","author":"Seiyama","year":"1962","journal-title":"Anal. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1023\/A:1014405811371","article-title":"Conduction Model of Metal Oxide Gas Sensors","volume":"7","author":"Barsan","year":"2001","journal-title":"J. Electroceramics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1002\/adma.200401101","article-title":"\u03b1-Fe2O3 Nanotubes in Gas Sensor and Lithium-Ion Battery Applications","volume":"17","author":"Chen","year":"2005","journal-title":"Adv. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/S0925-4005(97)00199-8","article-title":"Grain Size Control in Nanocrystalline In2O3 Semiconductor Gas Sensors","volume":"44","author":"Gurlo","year":"1997","journal-title":"Sens. Actuators B Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1624","DOI":"10.1021\/acssensors.0c00113","article-title":"WO3-Based Gas Sensors: Identifying Inherent Qualities and Understanding the Sensing Mechanism","volume":"5","author":"Staerz","year":"2020","journal-title":"ACS Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/0925-4005(91)80207-Z","article-title":"Grain Size Effects on Gas Sensitivity of Porous SnO2-Based Elements","volume":"3","author":"Xu","year":"1991","journal-title":"Sens. Actuators B Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/0925-4005(93)00873-W","article-title":"Conduction Models in Gas-Sensing SnO2 Layers: Grain-Size Effects and Ambient Atmosphere Influence","volume":"17","year":"1994","journal-title":"Sens. Actuators B Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/0925-4005(91)80213-4","article-title":"New Approaches for Improving Semiconductor Gas Sensors","volume":"5","author":"Yamazoe","year":"1991","journal-title":"Sens. Actuators B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2207","DOI":"10.1149\/1.2055088","article-title":"Grain-Size Effects in Tungsten Oxide-Based Sensor for Nitrogen Oxides","volume":"141","author":"Tamaki","year":"1994","journal-title":"J. Electrochem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/0250-6874(83)85034-3","article-title":"Effects of Additives on Semiconductor Gas Sensors","volume":"4","author":"Yamazoe","year":"1983","journal-title":"Sens. Actuators"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1798","DOI":"10.1143\/JJAP.27.1798","article-title":"Electronic Interaction between Metal Additives and Tin Dioxide in Tin Dioxide-Based Gas Sensors","volume":"27","author":"Matsushima","year":"1988","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/0250-6874(88)80047-7","article-title":"A Selective CO Sensor Using Ti-Doped \u03b1-Fe2O3 with Coprecipitated Ultrafine Particles of Gold","volume":"13","author":"Kobayashi","year":"1988","journal-title":"Sens. Actuators"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/0925-4005(90)80180-8","article-title":"Model Studies of SnO2-Based Gas Sensors: Vacancy Defects and Pd Additive Effects","volume":"1","author":"Semancik","year":"1990","journal-title":"Sens. Actuators B Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2183","DOI":"10.1021\/nl070160+","article-title":"ZnO Nanotube Based Dye-Sensitized Solar Cells","volume":"7","author":"Martinson","year":"2007","journal-title":"Nano Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4087","DOI":"10.1002\/adma.200803827","article-title":"ZnO Nanostructures for Dye-Sensitized Solar Cells","volume":"21","author":"Zhang","year":"2009","journal-title":"Adv. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2005","DOI":"10.1021\/nl051501r","article-title":"Ultraviolet Electroluminescence from ZnO\/Polymer Heterojunction Light-Emitting Diodes","volume":"5","author":"Word","year":"2005","journal-title":"Nano Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"L643","DOI":"10.1143\/JJAP.44.L643","article-title":"Blue Light-Emitting Diode Based on ZnO","volume":"44","author":"Tsukazaki","year":"2005","journal-title":"Jpn. J. Appl. Phys. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4131","DOI":"10.1016\/j.tsf.2011.04.067","article-title":"Development of Ga-Doped ZnO Transparent Electrodes for Liquid Crystal Display Panels","volume":"520","author":"Yamamoto","year":"2012","journal-title":"Thin Solid Film."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.tsf.2005.01.066","article-title":"Recent Advances in ZnO Transparent Thin Film Transistors","volume":"487","author":"Fortunato","year":"2005","journal-title":"Thin Solid Films"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.snb.2010.07.009","article-title":"Counterintuitive Sensing Mechanism of ZnO Nanoparticle Based Gas Sensors","volume":"150","author":"Han","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.snb.2012.05.068","article-title":"Citrate-Assisted Hydrothermal Synthesis of Single Crystalline ZnO Nanoparticles for Gas Sensor Application","volume":"173","author":"Rai","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1016\/j.sna.2017.10.021","article-title":"Room-Temperature Gas Sensing of ZnO-Based Gas Sensor: A Review","volume":"267","author":"Zhu","year":"2017","journal-title":"Sens. Actuators A Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1959","DOI":"10.1021\/acs.analchem.7b04048","article-title":"Ultraselective Toluene-Gas Sensor: Nanosized Gold Loaded on Zinc Oxide Nanoparticles","volume":"90","author":"Suematsu","year":"2018","journal-title":"Anal. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"9881","DOI":"10.1038\/s41598-019-46247-z","article-title":"A Highly Responsive NH3 Sensor Based on Pd-Loaded ZnO Nanoparticles Prepared via a Chemical Precipitation Approach","volume":"9","author":"Mhlongo","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/j.snb.2010.05.052","article-title":"Synthesis and Gas Sensing Characteristics of Highly Crystalline ZnO-SnO2 Core-Shell Nanowires","volume":"148","author":"Hwang","year":"2010","journal-title":"Sens. Actuators B Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"57967","DOI":"10.1039\/C4RA10659H","article-title":"Synthesis and Gas Sensor Application of ZnFe2O4\u2212ZnO Composite Hollow Microspheres","volume":"4","author":"Wang","year":"2014","journal-title":"RSC Adv."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1063\/1.3046726","article-title":"Gas Sensing Properties of Defect-Controlled ZnO-Nanowire Gas Sensor","volume":"93","author":"Ahn","year":"2008","journal-title":"Appl. Phys. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.snb.2019.01.127","article-title":"Complex-Surfactant-Assisted Hydrothermal Synthesis of One-Dimensional ZnO Nanorods for High-Performance Ethanol Gas Sensor","volume":"286","author":"Zhao","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.cattod.2008.01.013","article-title":"DRIFT Study of the Interaction of NO and O2 with the Surface of Ce0.62Zr0.38O2 as DeNOx Catalyst","volume":"137","author":"Adamowska","year":"2008","journal-title":"Catal. Today"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"38007","DOI":"10.1038\/srep38007","article-title":"Surface Protonics Promotes Catalysis","volume":"6","author":"Manabe","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"14018","DOI":"10.1021\/ja1064262","article-title":"Metallic Corner Atoms in Gold Clusters Supported on Rutile Are the Dominant Active Site during Water-Gas Shift Catalysis","volume":"132","author":"Williams","year":"2010","journal-title":"J. Am. Chem. Soc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"129004","DOI":"10.1016\/j.snb.2020.129004","article-title":"Unraveling the Surface Chemistry of CO Sensing with In2O3 Based Gas Sensors","volume":"326","author":"Boehme","year":"2021","journal-title":"Sens. Actuators B Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/j.jascer.2016.06.002","article-title":"Efficient Solution Route to Transparent ZnO Semiconductor Films Using Colloidal Nanocrystals","volume":"4","author":"Suehiro","year":"2016","journal-title":"J. Asian Ceram. Soc."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"17574","DOI":"10.1021\/jp4045226","article-title":"Pore and Particle Size Control of Gas Sensing Films Using SnO2 Nanoparticles Synthesized by Seed-Mediated Growth: Design of Highly Sensitive Gas Sensors","volume":"117","author":"Kida","year":"2013","journal-title":"J. Phys. Chem. C"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2228","DOI":"10.1021\/acssensors.9b00975","article-title":"Current Understanding of the Fundamental Mechanisms of Doped and Loaded Semiconducting Metal-Oxide-Based Gas Sensing Materials","volume":"4","author":"Degler","year":"2019","journal-title":"ACS Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1322","DOI":"10.1021\/acssensors.6b00477","article-title":"Gold-Loaded Tin Dioxide Gas Sensing Materials: Mechanistic Insights and the Role of Gold Dispersion","volume":"1","author":"Degler","year":"2016","journal-title":"ACS Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"35485","DOI":"10.1021\/acsami.6b13006","article-title":"Ultrasensitive Detection of Volatile Organic Compounds by a Pore Tuning Approach Using Anisotropically Shaped SnO2 Nanocrystals","volume":"8","author":"Kida","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"23908","DOI":"10.1021\/jp409831t","article-title":"In Situ DRIFTS-MS Study of the Anaerobic Oxidation of Ethanol over Spinel Mixed Oxides","volume":"117","author":"Ochoa","year":"2013","journal-title":"J. Phys. Chem. C"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1016\/j.jcat.2004.08.024","article-title":"In Situ DRIFT-Mass Spectrometry Study of the Ethanol Steam-Reforming Reaction over Carbonyl-Derived Co\/ZnO Catalysts","volume":"227","author":"Llorca","year":"2004","journal-title":"J. Catal."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.apcatb.2006.06.001","article-title":"Adsorption and Reactions of Ethanol and Ethanol-Water Mixture on Alumina-Supported Pt Catalysts","volume":"69","author":"Erdohelyi","year":"2007","journal-title":"Appl. Catal. B Environ."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1016\/j.jcat.2006.10.018","article-title":"Steam Reforming of Ethanol over Pt\/Ceria with Co-Fed Hydrogen","volume":"245","author":"Jacobs","year":"2007","journal-title":"J. Catal."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s10562-010-0476-z","article-title":"Adsorption\/Desorption Behavior of Ethanol Steam Reforming Reactants and Intermediates over Supported Cobalt Catalysts","volume":"141","author":"Song","year":"2011","journal-title":"Catal. Lett."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/16\/6277\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:12:59Z","timestamp":1760141579000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/16\/6277"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,20]]},"references-count":42,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["s22166277"],"URL":"https:\/\/doi.org\/10.3390\/s22166277","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,20]]}}}