Effect of Silver Promoter on the H₂ Gasochromic Recovery Behavior of Pt-Decorated WO₃ Nanowires

The hydrogen gasochromic phenomenon offers a new strategy for real-time sensing technologies for hydrogen leakage to ensure hydrogen safety. However, the limited recovery kinetics impede the cycling and further practical applications. Herein, we designed a series of PtAg-decorated WO₃ nanowires via the chemical reduction deposition method, which could exhibit obvious and reversible color changes for H₂ detection. With the assistance of Ag, the oxygen adsorption and dissociation were accelerated; then, the sample could exhibit a constant rapid recovery rate. The crystalline Pt-Ag/WO₃ nanowires could attain a 50% recovery degree within 52 s, and the recovery time of the Pt-Ag/WO₃ sample was reduced to one fifth that of Pt/WO₃. This study provides a fundamental solution to the challenge of slow recovery kinetics in H₂ gasochromic crystalline materials.