Investigation of NO2 adsorption on reduced graphene oxide

Abstract The adsorption of NO 2 on reduced graphene oxide (RGO) is investigated using in situ infrared microspectroscopy and density functional theory (DFT) calculations. NO 2 /RGO differential absorption spectra show a broadband modulation and the appearance of several vibrational absorption bands, indicating several coexisting adsorbate species. We find that NO 2 molecules react with native epoxide groups to form nitrate species. Consequently, the effect of NO 2 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.