Gas Sensing and Electrochemical Behaviors of Ag-doped 3D Spherical WO₃ Assembled by Nanostrips to Formaldehyde

摘要

A novel Ag-doped WO3 sensing material was successfully prepared via a facile hydrothermal methodcombining with a wet dipping process. The phase composition and micromorphology of the asobtained samples were characterized by X-ray diffraction (XRD) and field emission scanning electronmicroscope (SEM) technology. The electrochemical behavior and sensing were investigated, theresults demonstrated that the vibration in resistance of Ag-doped WO3 was approximately 3.5 timeshigher than the pure one after contacting formalin, and a higher response of 10.3 to 100 ppm HCHOwas exhibited at working temperature of 250 °C, which was better than the pure WO3 of 6.5 at 350 °C,the response/recovery time was shorted to 3 s/3 s. The enhanced of gas sensing behavior of WO3 afterintroducing Ag could be attributed to the hetero-structure and the catalysis role of silver. The Agdoped WO3 is expected to be a promising in HCHO gas-sensing practical applications.