The hierarchical nanostructured Co-doped WO3/carbon and their improved acetone sensing performance

Abstract

Hierarchical nanostructured Co-doped WO3 with carbon as template has been successfully synthesised through facile sol-gel method. The synthesised Co-doped WO3 was characterized by X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy, Energy dispersive X-ray spectrometry, and Brunauer-Emmett-Teller and X-ray photoelectron spectroscopy. The gas sensing properties of WO3 doped with Co from 0 to 0.8 wt % were also investigated on various VOCs. The fabricated sensor based on 0.6 wt% Co-doped WO3 with carbon as a template showed good sensitivity, selectivity, fast response and recovery time towards 1.5 ppm of acetone at 50 °C under 90% relative humidity. The excellent gas sensing properties could be attributed to high surface area, small crystallite size, defect of WO3 and Co catalysis effect which promotes gas adsorption and most importantly the stabilized monoclinic phase of WO3, which accounts for the good selectivity.