Preparation and sensing properties of mesoporous ZnO–rGO composites based on in situ hydrothermal synthesis

Abstract

Zinc oxide/graphene (ZnO–rGO, rGO is short for reduced graphene) nano-composites were prepared by in situ reduction of zinc acetate((CH3COO)2Zn·2H2O) and graphene oxide (GO) with a simple hydrothermal process assisted with Pluronic P123 triblock copolymer. Adsorbents of the gas sensing devices based on nanocomposite were prepared by coating method. The films have mesoporous structures and contain nano-crystalline phase, as evidenced from N2 adsorption–desorption isotherms, X-ray diffraction and high resolution scanning electron microscopy. Gas sensing properties of pure ZnO and ZnO–rGO nano-composites were investigated in the temperature range of 100–300 °C. Compared with ZnO, ZnO–rGO nano-composite samples have enhanced hydrogen sulfide sensing properties. When the concentration of hydrogen sulfide reached 50 ppm, sensitivity of ZnO–rGO (5 wt%) reached 55.91 at 160 °C, which was about dozens of times higher than that of pure ZnO.