Preparation of porous silicon/Pd-loaded WO3 nanowires for enhancement of ammonia sensing properties at room temperature

A sensitive resistive-type gas sensor based on porous silicon (PS)/Pd-loaded WO3 nanowires (NWs) was successfully synthesized via facile methods for detection of ammonia at room temperature. PS/WO3 NWs was synthesized by thermal evaporating W powder on the PS substrate, and Pd nanoparticles were decorated on the surface of WO3 NWs by in-situ reduction method. Compared with PS/WO3 NWs and Pd-loaded WO3 NWs, the PS/Pd-loaded WO3 NWs showed an enhanced response to ammonia at a low concentration down to 1 ppm and exhibited good selectivity, short response-recovery time at room temperature. The improved sensing characteristics indicated that the decoration of Pd NPs is effective for enhancing gas sensing performance.