Enhanced ethanol sensing properties of WO3 modified $TiO_2$ nanorods

Abstract

Pristine and WO3 decorated $TiO_2$ nanorods (NRs) were synthesised to investigate n-n-type heterojunction gas sensing properties. $TiO_2$ NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass (FTO) substrates. Then, tungsten was sputtered on the $TiO_2$ 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 $TiO_2$ NRs with WO3