W-doped nanoporous TiO2 for high performances sensing material toward acetone gas

Abstract

W-doped TiO2 with nanoporous structure was synthesized by a one-step low temperature hydrothermal method using TiOSO4 and (NH4)6H2W12O40•xH2O as titanium and tungsten sources. Structure, morphology, specific surface area and chemical state of samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). W-doped nanoporous TiO2 samples were used as sensing materials of indirect-heating sensors and their gas-sensing performances were studied to detect acetone. The experimental results show that 7.5% W-doped nanoporous TiO2 can adsorb more oxygen molecules on the surface and provide large amount of active reaction sites on interface to profit reaction between material and gas molecules. The gas sensor based on 7.5% W-doped nanoporous TiO2 exhibits good gas-sensing performances, including high gas response value, shortened response/recovery time and good reproducibility, which make it a promising candidate in acetone detection. Apart from these, the mechanism related to the advanced properties was also investigated and presented.