Synergistic effect of PdO and parallel nanowires assembled CuO microspheres enables high performance room-temperature H2S sensor

Abstract

High-performance semiconductor gas sensors comprising of metal oxides have offered appealing promise to environment monitor devices but remain challenging due to their high working temperature and sluggish response/recovery speed. Here we report a simple impregnation method that utilizing the high catalytic activity of palladium oxide activates copper oxide parallel nanowires assembled hierarchical microspheres (PdO-CuO NWMs). And then gas-sensing devices with different decorating concentrations were fabricated to investigate their sensing performance on hydrogen sulfide (H2S). It was demonstrated that the CuO microspheres with 2 wt% PdO decorating concentration is the optimum, with high response of 6.8 and extremely short response/recovery time of 1.8/4.1 s towards 50 ppm H2S at 30 °C, effective enhancing the response (4.9–50 ppm H2S) and working temperature (150 °C) of pristine CuO NWMs sensor. The boosting sensing performance of our PdO-CuO NWMs gas sensor was attributed to the synergistic effect of high catalytic noble nanoparticles and hierarchical structures. The coupling strategy offers new insights to explore room temperature and real-time monitoring gas sensors.