Two-step hydrothermal fabrication of CeO2-loaded MoS2 nanoflowers for ethanol gas sensing application

Abstract CeO2 nanoparticles-decorated MoS2 nanoflowers were prepared through a two-step hydrothermal method. The morphologies and structures of the synthesized MoS2/CeO2 samples were characterized via numerous characterization methods. It can be seen that CeO2 nanoparticles tightly adhered to the surfaces of MoS2 nanoflowers. Compared with pure MoS2, the better ethanol gas sensing performance is got after CeO2 doping, especially the obviously increased response value and shortened response-recovery time. In addition, considering the influence of humidity on the gas sensing, the responses of the composite sensor to ethanol gas under different humidity conditions were also compared. The greatly enhanced sensing performance of the MoS2/CeO2 composite sensor was mainly attributed to the variable valence state of cerium ions and the synergistic effects of MoS2 nanoflowers and CeO2 nanoparticles. Meanwhile, the ethanol gas detection circuit was constructed by combining the MoS2/CeO2 sensor and the microcontroller, which can realize the real-time display of gas concentration and the over-limit alarm.