Xylene gas sensor based on Au-loaded WO_3·H_2O nanocubes with enhanced sensing performance

摘要

In this work, Au was employed as an ideal dopant to obtain enhanced sensing performance of xylene gas sensor. Firstly, the as-perpared Au-doped WO_3· H_2O powder was synthesized by a facile and efficient hydrothermal method. Then various techniques including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectrometer (EDX) were employed to investigate the morphology, microstructure, crystalline nature and chemical compositions of the as-prepared Au-doped WO_3·H_2O nanomaterials. The morphologies of the nanomate-rials could be easily controlled by changing the atomic percentage (at%) of Au (0.15 at%, 0.30 at%, 0.45 at%) in the precursor solutions. And it have been attested that the 0.30 at% Au-doped WO_3·H_2O-based sensor realized higher gas response of 26.4-5 ppm xylene at 255 ℃, faster response/recovery speed and stronger selectivity to target gas compared with the unloaded one. Furthermore, the detection limit could be as low as 200 ppb level. Hence, Au-loaded WO_3·H_2O nanomaterial could be a promising material applied in xylene gas sensor. Also, the mechanism involved in the improving xylene sensing properties of Au/WO3·H2O was discussed.