▎ 摘　　要

Graphene oxide nanomaterials have been synthesized from Powder River Basin coal using an alternative nitric acid method. The absorption at ultraviolet-visible light energies and thermal decomposition properties of GO derived from raw and charred coal are comparable to graphene oxide fabricated using the improved Hummers' method. Similar observations are extended for coal residues, making coal a promising candidate for an environmentally friendly synthesis approach. The electrical conductivity of powder coal char reduced graphene oxide via this new method, is increased to 4800 S m(-1) at 2500 degrees C, comparable to the improved Hummers' method. For coal-derived graphene nanomaterials, an additional Raman feature D '' related to the amorphous phase in carbonaceous materials is found. The consideration of this feature along with the ratio of sp2-hybridized carbon atoms to structural defects, second-order Raman modes, and complementary X-ray diffraction and photoelectron spectroscopy is used to characterize the properties of thermally reduced graphene oxide nanomaterials.