Synthesis of ternary intercalation compounds in the graphite-HNO3-R (R = H2SO4, H3PO4, CH3COOH) systems

The reactions of stage II-IV graphite nitrates with concentrated H2SO4, H3P O4, and CH3COOH were studied at graphite : acid weight ratios from 3 : 1 to 1 : 1. The results demonstrate that the reactions in question follow diffe rent paths. In the graphite nitrate-H2SO4 system, the reaction decreases th e stage index and yields a ternary graphite intercalation compound. The con tents of intercalated HNO3 and H2SO4 are controlled by the amount of H2SO4 and the stage index of the parent graphite nitrate. The reaction between gr aphite nitrate and H3PO4 leads to partial replacement of HNO3 by H3PO4, inc reasing the identity period without changes in the stage index. The results for the graphite nitrate-CH3COOH system provide no direct evidence for the formation of an intercalation compound with HNO3 and CH3COOH. It is shown that varying the nature and amount of the second intercalate species opens up possibilities for preparing oxidized graphite with controlled physicoche mical properties.