An innovative method for enhancing the hydrogen gasochromic performance of mesoporous Pt/WO3 films

WO 3 -based optical hydrogen sensors, while advantageous due to their ignition-free operation and resistance to electromagnetic interference, face limitations due to slow response kinetics in hydrogen gasochromic processes. This study presents a novel post-treatment method using aqueous sulfuric acid, which significantly enhances the response speed of mesoporous Pt/WO 3 films. After treatment, the films exhibit an ultrashort response time of 2.4 s towards 4% H 2 /Ar, a marked improvement from 7.1 s prior to the treatment. The treated films also show excellent reversibility of 120 gasochromic cycles. The adsorbed acid layer is proved to be the cause of accelerated hydrogen gasochromic response. This exceptional performance is attributed to increased proton conductivity and the high porosity of the mesoporous structure. A modified model is proposed for the acceleration effect by acid post-treatment. Our post-treatment method represents a significant advancement in the reliable detection of hydrogen leaks at room temperature.