Metal-organic framework-derived ZnO decorated with CuO for ultra-high response and selectivity H2S gas sensor

Fast response recovery time and high response value are very necessary indicators for H 2 S sensors in the past few years. As H 2 S is a toxic gas that has great threat to human life, research on H 2 S gas sensors has received widespread attention. In this work, H 2 S gas sensors with high response value, excellent selectivity and fast response/recovery time were prepared by liquid phase synthesis method. Firstly, ZIF-8 (zeolite imidazolate framework-8) metal-organic framework derived ZnO was synthesized. Then high performance CuO/ZnO sensing materials modified with different amounts of CuO were synthesized using ZnO as the pristine material and CuO as the sensitizing material. Furthermore, the gas sensing test was conducted and the results show that the synthesized CuO/ZnO has significantly enhanced sensing performance to H 2 S. The highest response to 10 ppm H 2 S is 941 at a relatively low working temperature of 175 °C, which is 80 times higher than that of ZIF-8 derived ZnO. Moreover, the sensor based on CuO sensitized ZnO also showed excellent selectivity, fast response/recovery property and good moisture resistance. The enhanced gas sensing performance is mainly attributed to the formation of p-n heterojunction and the strong chemical affinity and catalytic performance of CuO for H 2 S. • CuO composite ZnO nanoparticles were prepared by a novel liquid phase synthesis method. • CuO composite ZnO nanoparticles exhibit excellent selectivity to H 2 S. • The sensor has a high response of 941 and good moisture resistance of 416 (90% RH) to 10 ppm H 2 S at 175 ℃. • The sensing materials in this experiment are promising candidates for H 2 S gas sensing in environmental monitoring.