▎ 摘　　要

Reduced graphene oxide (RGO)-based NO2 sensors have attracted considerable attention due to their excellent advantages of low power consumption and manufacturability to facilitate massive deployment. However, it is still a great challenge to fabricate RGO-based room-temperatureNO(2) sensors with excellent sensing performances. Herein, we have demonstrated a combined surface modification and heteroatom doping approach to enhance the sensing performances of RGO-based room-temperature NO2 sensors, where SnO2 nanoparticles modified nitrogen-doped RGO (SnO2/N-RGO) hybrids had been used as sensing materials. The SnO2/N-RGO hybrids were prepared by hydrothermal synthesis method using SnCl4, GO and urea as precursors. The combined characterizations of X-ray diffraction (XRD), energy-dispersive X-ray spectrometer (EDS), elemental mapping, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), Raman spectra as well as N-2 sorption isotherm were used to characterize the materials thus obtained, indicating the successful preparation of SnO2/N-RGO hybrids. During the hydrothermal progress, SnCl4 conversed into SnO2 nanoparticles (NPs), and GO was reduced into RGO, while urea was decomposed into nitrogen-containing molecule and doped into RGO. It is found that SnO2 NPs with the size of 3-5 nm are uniformly dispersed on N-RGO nanosheets. Most importantly, SnO2/N-RGO hybrids-based sensor exhibits superior sensing performances toward NO2 operated at room temperature, which are better than those of pure RGO and SnO2/RGO hybrids. For example, SnO2/NRGO hybrids show response of 1.38 to 5 ppm NO2 with the response time and recovery time of 45 s and 168 s. The excellent sensing, performances are attributed to incorporation of N atoms into RGO and the modification of RGO with SnO2 NPs. This novel sensor based on SnO2/N-RGO hybrids promises to provide an essential sensing platform for the detection of NO2 with excellent sensing performances at room temperature. (C) 2016 Published by Elsevier B.V.