▎ 摘　　要

In this paper, palladium (Pd)-doped tin oxide (SnO2)/partially reduced graphene oxide (PRGO) and Pd doped SnO2/reduced graphene oxide (rGO) nanocomposites are synthesized via a simple hydrothermal route. Field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD) are used to characterize the structure, morphology and composition of the crystalline phases of the prepared gas sensitive materials. The FESEM images confirm the existence of homogeneous dispersion of Pd-doped Sn02 nanoparticles anchored onto the rGO/PRGO nanosheets. Then the application of these nanocomposites is investigated as methane (CH4) gas sensor and compared with each other. The performance of sensors is studied toward CH4 gas concentrations ranging from 800 to 16000 part per million (ppm) at room temperature. The fabricated sensors show an enhancement in the electrical conductivity with increasing CH4 concentration. The synthesized Pd-doped SnO2/rGO nanocomposite in comparison with Pd-doped SnO2/PRGO, exhibits better sensitivity, excellent selectivity and relatively short response time to CH4 at room temperature. The excellent sensing performance of sensor could be ascribed to the presence of Pd nanoparticles and rGO nanosheets in the sensing nanocomposite. (C) 2017 Elsevier Ltd. All rights reserved.