Exfoliated graphite from various intercalation compounds

Five different intercalation compounds (GICs) with H2SO4, FeCl3, Na-tetrahydrofuran (THF), K-THF and Co-THF were prepared from flaky natural graphite powder with the average particle size of 400 μm. The exfoliated graphites were prepared from the GICs by rapid heating up to 1000°C and were observed with a scanning electron microscope. A remarkable difference in morphology was observed between the exfoliated graphites prepared from acceptor- and donor-type GICs; the former consists of large balloons across the original graphite flakes, the latter of small balloons with tiny graphite layers. Small particles of Fe2O3 were found on the surface of the exfoliated graphite prepared from FeCl3-GIC. In the exfoliated graphite from Co-THF-GIC, very tiny particles were detected, which seemed to be metallic cobalt. In those from Na- and K-THF-GICs, no alkali metals were detected even by XPS.