Preparation of Tungsten Oxide Nanoplate Thin Film and its Gas Sensing Properties

Tungsten oxide is a kind of multifunctional materials with excellent properties for gas sensing, electrochromic and photocatalytic applications. In this study, Tungsten oxide nanoplate thin film was prepared by hydrothermal methods. The as-prepared thin film is composed of tungsten trioxide hydrate nanoplates, which are randomly orientate on the surface. The as-grown nanoplate thin film shows good sensitivity to H2 gas. Dehydration and phase transition to γ-phase tungsten trioxide were found after annealing, and the sensitivity as well as the response time to H2 were improved. We found that the nanoplate in the annealing sample bursts, which raises the surface-to-volume ratio for better hydrogen diffusion and reaction. The sensing mechanism was discussed. The findings provide a way to control the structure and surface morphology for improving the H2 sensing properties of tungsten oxide.