Synthesis of fluorine-graphite intercalation compounds by elemental fluorine and high oxidation-state transition-metal fluorides

Abstract

Fluorine-graphite intercalation compounds have been synthesized using high purity fluorine gas and high oxidation-state transition-metal fluorides, AgF3 and NiF3, at room temperature and at -78°C. At room temperature, a mixture of stage 1+2-4 compounds with compositions, C4.2F to C14.6F were obtained. On the other hand, stage 2-4 compounds with compositions C5.6F to C14.2F were synthesized at -78°C. The fluorinating ability of AgF3 and NiF3 has been shown more clearly at room temperature because a small amount of fluorine was intercalated/absorbed into graphite at -78°C without catalysts. XPS spectra show that ionic, nearly ionic, semi-covalent and covalent fluorines coexist in the CxF samples, and that the covalency of C-F bonding increases with decreasing stage number. Copyright © 1996 Elsevier Science Ltd.