P-type Co3O4 porous nanosheets-based H2S gas sensor with high performance
摘要
Industrial production, environmental monitoring, and public safety impose urgent demands for high-performance H2S gas sensors, as even trace amounts of H2S pose serious threats to human health. In this study, a novel material, Co3O4 porous nanosheets (Co3O4-PNSs), was successfully prepared. These nanosheets exhibit a porous nanostructure with dimensions ranging from approximately 100–500 nm, containing numerous narrow nanopores that partition them into elongated strips. The H2S sensing performance of the Co3O4-PNSs-based sensor was evaluated at a temperature of 270 °C. The sensor demonstrated °C excellent performance, including high sensitivity (10.2 for 100 ppm), rapid response/recovery times (410/715s for 50 ppm), superior selectivity, good repeatability, and high stability. This sensor operates on the surface electrical regulation mechanism of p-type Co3O4: oxygen adsorption in air forms O−, thickening the hole accumulation layer and reducing resistance; upon exposure to H2S, the reaction releases electrons, thinning the hole layer and increasing resistance, thereby enabling detection. Its ppb-level high sensitivity benefits from the enhanced surface activity due to the Co2⁺/Co3⁺ redox couple, as well as the large specific surface area and efficient gas diffusion provided by the porous nanosheet structure. This work proposes a concise and efficient synthesis strategy for the successful fabrication of a sensor with excellent overall performance.