Double-walled carbon nanotubes (DWCNTs), multi-walled carbon nanotubes (MWCNTs), few-layer graphene (FLG) and graphene nanoplatelets (GNPs) were chemically modified by refluxing in HNO3 at 3 M for 24 h rigorously in the same way. The oxidized samples have been characterized by means of several complementary characterization techniques : transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) under air and TGA coupled with a mass spectrometry (TGA-MS) under He. The dataset provides morphological, structural and chemical characterizations of the four chemically treated carbon nanomaterials.