{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T08:52:25Z","timestamp":1773823945961,"version":"3.50.1"},"reference-count":44,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T00:00:00Z","timestamp":1639094400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004761","name":"Natural Science Foundation of Hainan Province","doi-asserted-by":"publisher","award":["620QN239"],"award-info":[{"award-number":["620QN239"]}],"id":[{"id":"10.13039\/501100004761","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Scientific Research Starting Foundation of Hainan University","award":["KYQD(ZR)-20052"],"award-info":[{"award-number":["KYQD(ZR)-20052"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>CeO2\/ZnO-heterojunction-nanorod-array-based chemiresistive sensors were studied for their low-operating-temperature and gas-detecting characteristics. Arrays of CeO2\/ZnO heterojunction nanorods were synthesized using anodic electrodeposition coating followed by hydrothermal treatment. The sensor based on this CeO2\/ZnO heterojunction demonstrated a much higher sensitivity to NO2 at a low operating temperature (120 \u00b0C) than the pure-ZnO-based sensor. Moreover, even at room temperature (RT, 25 \u00b0C) the CeO2\/ZnO-heterojunction-based sensor responds linearly and rapidly to NO2. This sensor\u2019s reaction to interfering gases was substantially less than that of NO2, suggesting exceptional selectivity. Experimental results revealed that the enhanced gas-sensing performance at the low operating temperature of the CeO2\/ZnO heterojunction due to the built-in field formed after the construction of heterojunctions provides additional carriers for ZnO. Thanks to more carriers in the ZnO conduction band, more oxygen and target gases can be adsorbed. This explains the enhanced gas sensitivity of the CeO2\/ZnO heterojunction at low operating temperatures.<\/jats:p>","DOI":"10.3390\/s21248269","type":"journal-article","created":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T08:17:58Z","timestamp":1639124278000},"page":"8269","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":39,"title":["Low-Operating-Temperature NO2 Sensor Based on a CeO2\/ZnO Heterojunction"],"prefix":"10.3390","volume":"21","author":[{"given":"Kai","family":"Sun","sequence":"first","affiliation":[{"name":"State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1009-6531","authenticated-orcid":false,"given":"Guanghui","family":"Zhan","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China"}]},{"given":"Hande","family":"Chen","sequence":"additional","affiliation":[{"name":"Sensor Centre, Hainan Unican Science and Technology Innovation Institute, Haikou 570228, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7325-8182","authenticated-orcid":false,"given":"Shiwei","family":"Lin","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"460","DOI":"10.1097\/EDE.0000000000000847","article-title":"Long-term Concentrations of Nitrogen Dioxide and Mortality: A Meta-analysis of Cohort Studies","volume":"29","author":"Atkinson","year":"2018","journal-title":"Epidemiology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"105876","DOI":"10.1016\/j.envint.2020.105876","article-title":"Short-term exposure to particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), and ozone (O3) and all-cause and cause-specific mortality: Systematic review and meta-analysis","volume":"142","author":"Orellano","year":"2020","journal-title":"Environ. Int."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1080\/0002889708506253","article-title":"Odor Threshold Levels for UDMH and NO2","volume":"31","author":"Rumsey","year":"1970","journal-title":"Am. Ind. Hyg. Assoc. J."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1118","DOI":"10.3390\/app8071118","article-title":"Research Progress of Gas Sensor Based on Graphene and Its Derivatives: A Review","volume":"8","author":"Wenchao","year":"2018","journal-title":"Appl. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"9957","DOI":"10.1021\/acsanm.1c01895","article-title":"Electrospun Nanofibers for Quartz Crystal Microbalance Gas Sensors: A Review","volume":"4","author":"Rianjanu","year":"2021","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Rezki, M., Septiani, N.L.W., Iqbal, M., Adhika, D.R., Wenten, I.G., and Yuliarto, B. Review\u2014Recent Advance in Multi-Metallic Metal Organic Frameworks (MM-MOF) and their Derivatives for Electrochemical Biosensor Application. J. Electrochem. Soc., 2021.","DOI":"10.1149\/1945-7111\/ac3713"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"112719","DOI":"10.1016\/j.bios.2020.112719","article-title":"Molecularly imprinted polymer-based electrochemical sensors for environmental analysis","volume":"172","author":"Rebelo","year":"2021","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2088","DOI":"10.3390\/s100302088","article-title":"Metal oxide gas sensors: Sensitivity and influencing factors","volume":"10","author":"Wang","year":"2010","journal-title":"Sensors"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1577","DOI":"10.1021\/acssensors.9b00259","article-title":"Mechanism of Sensitivity Enhancement of a ZnO Nanofilm Gas Sensor by UV Light Illumination","volume":"4","author":"Li","year":"2019","journal-title":"ACS Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"127489","DOI":"10.1016\/j.snb.2019.127489","article-title":"Al doped narcissus-like ZnO for enhanced NO2 sensing performance: An experimental and DFT investigation","volume":"305","author":"Zhang","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3152","DOI":"10.1021\/cm1001576","article-title":"Thermally Stable, Silica-Doped \u03b5-WO3 for Sensing of Acetone in the Human Breath","volume":"22","author":"Righettoni","year":"2010","journal-title":"Chem. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1701167","DOI":"10.1002\/admi.201701167","article-title":"Enhanced NOx Gas Sensing Properties of Ordered Mesoporous WO3\/ZnO Prepared by Electroless Plating","volume":"5","author":"Han","year":"2017","journal-title":"Adv. Mater. Interfaces"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"125830","DOI":"10.1016\/j.jhazmat.2021.125830","article-title":"Thin-layered MoS2 nanoflakes vertically grown on SnO2 nanotubes as highly effective room-temperature NO2 gas sensor","volume":"416","author":"Bai","year":"2021","journal-title":"J. Hazard. Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"127455","DOI":"10.1016\/j.snb.2019.127455","article-title":"Visible-light Activated Room Temperature NO2 Sensing of SnS2 Nanosheets Based Chemiresistive Sensors","volume":"305","author":"Gu","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"11016","DOI":"10.1038\/s41598-018-29363-0","article-title":"Low-Temperature Ionic Layer Adsorption and Reaction Grown Anatase TiO2 Nanocrystalline Films for Efficient Perovskite Solar Cell and Gas Sensor Applications","volume":"8","author":"Shaikh","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"14315","DOI":"10.1016\/j.ceramint.2015.07.063","article-title":"Enhanced hydrogen sensing performance of tungsten activated ZnO nanorod arrays prepared on conductive ITO substrate","volume":"41","author":"Vijayalakshmi","year":"2015","journal-title":"Ceram. Int."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1007\/s40820-014-0023-3","article-title":"Zinc Oxide Nanostructures for NO2 Gas\u2013Sensor Applications: A Review","volume":"7","author":"Kumar","year":"2015","journal-title":"Nano-Micro Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1561","DOI":"10.1007\/s10853-016-0450-2","article-title":"Synthesis of MoO3\/WO3 composite nanostructures for highly sensitive ethanol and acetone detection","volume":"52","author":"Sun","year":"2016","journal-title":"J. Mater. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"8475","DOI":"10.1039\/c2ee22310d","article-title":"ChemInform Abstract: Nanostructured Ceria-Based Materials: Synthesis, Properties, and Applications","volume":"5","author":"Sun","year":"2012","journal-title":"Energy Environ. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/1010-6030(94)03906-B","article-title":"Exploiting the interparticle electron transfer process in the photocatalysed oxidation of phenol, 2-chlorophenol and pentachlorophenol: Chemical evidence for electron and hole transfer between coupled semiconductors","volume":"85","author":"Serpone","year":"1995","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.molstruc.2015.05.057","article-title":"Effect of CeO2 coupling on the structural, optical and photocatalytic properties of ZnO nanoparticle","volume":"1099","author":"Sherly","year":"2015","journal-title":"J. Mol. Struct."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4725","DOI":"10.1016\/j.msec.2013.07.034","article-title":"Visible light induced degradation of methylene blue using CeO2\/V2O5 and CeO2\/CuO catalysts","volume":"33","author":"Saravanan","year":"2013","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"127319","DOI":"10.1016\/j.snb.2019.127319","article-title":"A transparent ZnO nanowire MEMS gas sensor prepared by an ITO micro-heater","volume":"304","author":"Hsueh","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.molcata.2015.08.013","article-title":"Investigation of photocatalytic effect of ZnO\u2013SnO2\/nano clinoptilolite system in the photodegradation of aqueous mixture of 4-methylbenzoic acid\/2-chloro-5-nitrobenzoic acid","volume":"409","author":"Khodami","year":"2015","journal-title":"J. Mol. Catal. A Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.ssc.2012.11.003","article-title":"One-step solvothermal synthesis of ZnO\u2013carbon composite spheres containing different amounts of carbon and their use as visible light photocatalysts","volume":"155","author":"Lian","year":"2013","journal-title":"Solid State Commun."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1021\/ic902104r","article-title":"In-Situ Powder X-ray Diffraction Investigation of Reaction Pathways for the BaCO3\u2212CeO2\u2212In2O3 and CeO2\u2212In2O3 Systems","volume":"49","author":"Bhella","year":"2010","journal-title":"Inorg. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"4229","DOI":"10.1002\/smll.201601507","article-title":"A New Strategy for Humidity Independent Oxide Chemiresistors: Dynamic Self-Refreshing of In2O3 Sensing Surface Assisted by Layer-by-Layer Coated CeO2 Nanoclusters","volume":"12","author":"Ji","year":"2016","journal-title":"Small"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1016\/j.cej.2016.07.014","article-title":"Well-dispersed nebula-like ZnO\/CeO2@HNTs heterostructure for efficient photocatalytic degradation of tetracycline","volume":"304","author":"Ye","year":"2016","journal-title":"Chem. Eng. J."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1080\/19443994.2014.922443","article-title":"Investigation of the photocatalytic activity of supported ZnO\u2013TiO2 on clinoptilolite nano-particles towards photodegradation of wastewater-contained phenol","volume":"55","author":"Bahrami","year":"2015","journal-title":"Desalin. Water Treat."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3718","DOI":"10.1021\/am300812n","article-title":"BiVO4\/CeO2 Nanocomposites with High Visible-Light-Induced Photocatalytic Activity","volume":"4","author":"Wetchakun","year":"2012","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1021\/ac0509859","article-title":"Improving the Linearity of Infrared Diffuse Reflection Spectroscopy Data for Quantitative Analysis: An Application in Quantifying Organophosphorus Contamination in Soil","volume":"78","author":"Samuels","year":"2006","journal-title":"Anal. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.saa.2015.06.094","article-title":"Synthesis, characterization, low temperature solid state PL and photocatalytic activities of Ag2O\u00b7CeO2\u00b7ZnO nanocomposite","volume":"151","author":"Subhan","year":"2015","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"7717","DOI":"10.1039\/C2CC31773G","article-title":"Efficient photocatalytic hydrogen evolution over hydrogenated ZnO nanorod arrays","volume":"48","author":"Lu","year":"2012","journal-title":"Chem. Commun."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.mssp.2013.09.020","article-title":"Improved visible-light-driven photocatalytic activity of CeO2 microspheres obtained by using lotus flower pollen as biotemplate","volume":"25","author":"Qian","year":"2014","journal-title":"Mater. Sci. Semicond. Process."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3140","DOI":"10.1021\/ja808433d","article-title":"Oxygen Vacancy Clusters Promoting Reducibility and Activity of Ceria Nanorods","volume":"131","author":"Liu","year":"2009","journal-title":"J. Am. Chem. Soc."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"913","DOI":"10.1016\/j.jssc.2008.01.031","article-title":"Characterization and activity of visible-light-driven TiO2 photocatalyst codoped with nitrogen and cerium","volume":"181","author":"Chao","year":"2008","journal-title":"J. Solid State Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3033","DOI":"10.1016\/j.apsusc.2008.08.058","article-title":"Carbon monoxide gas-sensing properties of CeO2\u2013ZnO thin films","volume":"255","author":"Durrani","year":"2008","journal-title":"Appl. Surf. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"4024","DOI":"10.1021\/am300835p","article-title":"Oxygen Vacancy Induced Band-Gap Narrowing and Enhanced Visible Light Photocatalytic Activity of ZnO","volume":"4","author":"Wang","year":"2012","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.snb.2013.11.069","article-title":"Enhanced sensing performance of relative humidity sensors using laterally grown ZnO nanosheets","volume":"193","author":"Tsai","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1016\/j.snb.2018.11.080","article-title":"Reduced graphene oxide hybridized with WS2 nanoflakes based heterojunctions for selective ammonia sensors at room temperature","volume":"282","author":"Wang","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"508","DOI":"10.1016\/j.snb.2015.08.085","article-title":"The n-ZnO\/n-In2O3 heterojunction formed by a surface-modification and their potential barrier-control in methanal gas sensing","volume":"222","author":"Ma","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"215702","DOI":"10.1088\/1361-6528\/ab73b4","article-title":"Preparation of pyramidal SnO\/CeO2 nano-heterojunctions with enhanced photocatalytic activity for degradation of tetracycline","volume":"31","author":"Zhang","year":"2020","journal-title":"Nanotechnology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"7207","DOI":"10.1109\/JSEN.2019.2916879","article-title":"Room Temperature Formaldehyde Sensing of Hollow SnO2\/ZnO Heterojunctions under UV-LED Activation","volume":"19","author":"Zhao","year":"2019","journal-title":"IEEE Sens. J."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1016\/S1005-0302(11)60113-8","article-title":"Role of ZnO-CeO2 Nanostructures as a Photo-catalyst and Chemi-sensor","volume":"27","author":"Khan","year":"2011","journal-title":"J. Mater. Sci. Technol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8269\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:45:04Z","timestamp":1760168704000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8269"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,10]]},"references-count":44,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["s21248269"],"URL":"https:\/\/doi.org\/10.3390\/s21248269","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,10]]}}}