EFFECT OF THE GRAPHITE OXIDE COMPOSITION ON THE STRUCTURE OF PRODUCTS OBTAINED BY SULFURIC ACID TREATMENT AT ELEVATED TEMPERATURES
S.G. Stolyarova1, E.S. Kobeleva1,2, I.P. Asanov1,2, A.V. Okotrub1,2, L.G. Bulusheva1,2
1Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National Research State University, Novosibirsk, Russia
Keywords: оксид графита, нагревание в серной кислоте, графен, дефекты, РФЭС, NEXAFS, graphite oxide, heating in sulfuric acid, graphene, defects, XPS
Abstract
The electronic structure and functional composition of the products of graphite oxide (GO) interaction with concentrated sulfuric acid (H2SO4) depending on the oxygen content in the precursor and the treatment temperature are studied. X-ray photoelectron spectroscopy measuring the near-edge Xray absorption fine structure at the CK edge, and infrared spectroscopy are used to show the reduction of the π-electron system of graphene planes at a temperature of 200° C. Aggregation of oxygen groups in GO containing more than 40 % of oxygen causes the formation of vacancy defects in the planes with oxygen groups at the edges. When the GO treatment temperature rises to 280°C, the oxidation of the basal plane π-regions occurs. The results can be the basis to control the functional composition, vacancy number and size in graphite materials.
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