tailieunhanh - Enhanced ethanol sensing properties of WO3 modified TiO2 nanorods

Pristine and WO3 decorated TiO2 nanorods (NRs) were synthesised to investigate n-n-type heterojunction gas sensing properties. TiO2 NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass (FTO) substrates. Then, tungsten was sputtered on the TiO2 NRs and thermally oxidised to obtain WO3 nanoparticles. The heterostructure was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. Fabricated sensor devices were exposed to VOCs such as toluene, xylene, acetone and ethanol, and humidity at different operation temperatures. | Turkish Journal of Chemistry Turk J Chem 2021 45 295-306 http chem TÜBİTAK Research Article doi kim-2008-46 Enhanced ethanol sensing properties of WO3 modified TiO2 nanorods Bekzat ABDIKADYR Alp KILIÇ Onur ALEV Serkan BÜYÜKKÖSE Zafer Ziya ÖZTÜRK Department of Physics Faculty of Science Gebze Technical University Kocaeli Turkey Received Accepted Published Online Final Version Abstract Pristine and WO3 decorated TiO2 nanorods NRs were synthesised to investigate n-n-type heterojunction gas sensing properties. TiO2 NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass FTO substrates. Then tungsten was sputtered on the TiO2 NRs and thermally oxidised to obtain WO3 nanoparticles. The heterostructure was characterised by X-ray diffraction XRD scanning electron microscopy SEM and energy-dispersive X-ray EDX spectroscopy. Fabricated sensor devices were exposed to VOCs such as toluene xylene acetone and ethanol and humidity at different operation temperatures. Experimental results demonstrated that the heterostructure has better sensor response toward ethanol at 200 C. Enhanced sensing properties are attributed to the heterojunction formation by decorating TiO2 NRs with WO3. Key words WO3 TiO2 gas sensor heterostructure nanorods ethanol 1. Introduction Volatile organic compounds VOCs such as ethanol acetone toluene xylene have been widely used in daily life especially in industrial applications. However VOCs induce some harmful effects for human health and environment 1-6 . In addition some VOCs have been referred as tracer compounds in the human exhaled breath for various diseases 7-9 . Moreover ethanol is the strongest indicator for detection of alcohol level in human breath 10 . Therefore proper and fast detection of various VOCs is very important for different applications such as traffic security environmental monitoring in-door air quality and breath analysis. There are .