Low-temperature synthesis of WO3 nanolamella and their sensing properties for xylene

Abstract

Tungsten trioxides (WO₃) are an important class of n-type semiconductor oxide materials with a wide band-gap. In this work, nanolamella of tungsten oxides have been successfully synthesized by a simple, facile and cost-effective route starting from Na₂WO₄ and subsequent calcination at 300 °C. The structure and morphology of the nanolamella were characterized by X-ray diffraction (XRD) scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and photoluminescence (PL), respectively. The morphologies of the prepared products can be tailored by changing the calcination temperature. The obtained WO₃ products were investigated as sensitive materials for the detection of xylene. On the basis of gas sensing tests, the sensor using WO₃ nanolamella after annealing at 300 °C for 2 h exhibited better gas sensing properties. The maximum response reached 47 to 100 ppm of xylene at 280 °C. These results indicated that the gas sensors based on WO₃ nanolamella express high and fast response and recovery characteristics to xylene, and the WO₃ nanolamella are promising sensitive materials for xylene detecting.