In-situ fabrication of ZnO nanoparticles sensors based on gas-sensing electrode for ppb-level H_2S detection at room temperature

The zinc oxide(Zn O) 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(H_2S) gas. The sphere-like Zn O NPs were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), x-ray diffraction(XRD), energy dispersive x-ray analysis(EDX), and their H2 S sensing performance were measured at room temperature. Testing results indicate that the Zn O NPs exhibit excellent response to H_2S gas at room temperature. The response value of the optimal sample to750 ppb H_2S 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 H_2S sensing performance. The corresponding reaction mechanism of H_2S detection was also discussed.