Ultrasensitive and selective CuO/GaN co-decorated SnO2 nanowire gas sensor with ppb-level detection of H2S gas

초록

H2S gas, which has a highly unpleasant odor, is highly toxic, flammable, and corrosive; hence, development of reliable, highly selective ppb-level sensitive H2S gas sensors is vital. Herein, we obtained SnO2 nanowires (NWs) through a vapor-liquid-solid mechanism and GaN nanoparticles (NPs) were decorated on them. Subsequently, CuO NPs were decorated on the GaN-decorated SnO2 NWs. Various characterization methods confirmed the formation of crystalline materials with NW morphology and the uniform dispersion of CuO and GaN NPs on SnO2 NWs with the desired chemical composition. A bare SnO2 NW gas sensor yielded a low response of 1.35-10 H2S at 300 degrees C, whereas after GaN and CuO/GaN co-decoration on SnO2 NWs, the responses increased to 37 and 7268, respectively. Furthermore, the optimal gas sensor yielded excellent repeatability, selectivity, and long-term stability. The enhanced output was stemmed from the transformation of CuO to CuS with high metallic conductance, the interface junctions formed between GaN and SnO2, and CuO and SnO2, which affect charge transport, and the availability of numerous abundant reaction sites attributed to the nanowire-based structural configuration.

키워드