▎ 摘　　要

The adsorption of NO2 on reduced graphene oxide (RGO) is investigated using in situ infrared microspectroscopy and density functional theory (DFT) calculations. NO2/RGO differential absorption spectra show a broadband modulation and the appearance of several vibrational absorption bands, indicating several coexisting adsorbate species. We find that NO2 molecules react with native epoxide groups to form nitrate species. Consequently, the effect of NO2 is, partially, to remove epoxide groups and their distortion of the low-energy electronic structure of graphene, while simultaneously hole-doping the substrate. These results are discussed and related to recent reports on the gas-sensing behavior of RGO. (C) 2015 Elsevier B.V. All rights reserved.