WO3 thin film gas sensors are prepared by DC reactive magnetron sputtering on unpolished alumina substrate and annealed in the dry air.The surface morphology of the film is analyzed by SEM and the crystalline phase of the film is scaled against XRD.In order to measure H2 gas sensitivity of WO3 thin film

a sealed test box is used.A sample is installed in the test box and the test gas is precisely pumped by an injector.Under 400 ℃ of annealing temperature and 270 ℃ of operating temperature

the hydrogen sensitivity of the thin film with a volume fraction of 3×10-4 hydrogen can reach maximum at 77.The response time is quite short and within 15 s.Therefore

with above-mentioned features

WO3 film can be treated as an ideal hydrogen gas sensing material.