Synthesis of highly dispersed ZnO nanoparticles on graphene surface and their acetylene sensing properties

This paper investigates the acetylene (C2H2) gas sensing performance of the ZnO/reduced graphene oxide (rGO) composite, synthesized by a solvothermal method. The system structure, morphology, and optical properties of the synthesized sensing composite were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and photoluminescence (PL) spectroscopy. The physical properties of the synthesized sensing composite showed a highly crystalline phase structure of ZnO and well dispersed ZnO nanoparticles affixed onto the reduced graphene oxide layer. A maximum sensor response value of 143 for 1000 ppm C2H2 at 250 °C was obtained for the optimized material ratio of ZnO and rGO (4:1). From the experimental results, it is evident that the synthesized composite had preferential detection of C2H2 gas with good selectivity, long-term stability, and fast response/recovery time at 250 °C, which suggests that a graphene oxide (GO) addition would be effective in improving the C2H2 sensing performance of ZnO based sensors.