Highly sensitive and fast-response hydrogen sensing of WO3 nanoparticles via palladium reined spillover effect.

Hydrogen sensing simultaneously endowed with fast response, high sensitivity and selectivity is highly desired in detecting hydrogen leakages such as in hydrogen-driven vehicles and space rockets. Here, hydrogen sensing reined via a hydrogen spillover effect has been developed using palladium nanoparticles photochemically decorated on WO3 nanoparticles (Pd-NPs@WO3-NPs). Theoretically, the Pd-NP catalysts and WO3-NP support are used to construct the hydrogen spillover system, in which Pd NPs possess high catalytic activity, promoting the electron transfer and therefore the reaction kinetics. Beneficially, the Pd-NPs@WO3-NP sensor prototypes toward 500 ppm hydrogen simultaneously exhibit fast response time (∼1.2 s), high response (Ra/Rg = 22 867) and selectivity at a working temperature of 50 °C. Such advanced hydrogen sensing provides an experimental basis for the smart detection of hydrogen leakage in the future hydrogen economy.