In-situ fabrication of ZnO nanoparticles sensors based on gas-sensing electrode for ppb-level H2S detection at room temperature*

Abstract

The zinc oxide (ZnO) nanoparticles (NPs) sensors were prepared in-situ on the gas-sensing electrodes by a one-step simple sol-gel method for the detection of hydrogen sulfide (H2S) gas. The sphere-like ZnO NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray analysis (EDX), and their H2S sensing performance were measured at room temperature. Testing results indicate that the ZnO NPs exhibit excellent response to H2S gas at room temperature. The response value of the optimal sample to 750 ppb H2S is 73.3%, the detection limit reaches to 30 ppb, and the response value is 7.5%. Furthermore, the effects of the calcining time and thickness of the film on the gas-sensing performance were investigated. Both calcining time and film thickness show a negative correlation with the H2S sensing performance. The corresponding reaction mechanism of H2S detection was also discussed.