Interaction of FeCl_3-Intercalated Graphite with Intercalants of Different Strengths

摘要

This paper examines reactions of stage Ⅰ and ⅡFeCl_3-graphite intercalation compounds (GICs) with intercalants of different strengths: nitric acid and tetrahydrofuran (THF). The reaction of GlC-FeCl_3 with nitric acid, a strong intercalant, leads to HNO_3 substitution for the FeCl_3 in the interlayer spaces of the graphite and formation of a stage Ⅱ GICs with HNO_3. THF, a weak intercalant, does not form any compounds with a stage Ⅰ or Ⅱ GIC with FeCl_3; instead, it diffuses to intercrystalline regions of the graphite host. Flash heating of the synthesized GICs in air leads to the formation of exfoliated graphite (EG) containing a-Fe_2O_3 particles, which has low bulk density, down to 6.5 g/L, and high ferric oxide content, up to 33 wt %. Reduction in flowing hydrogen at 600℃ leads to the formation of EG with up to 23 wt % α-Fe particles supported on it and with a saturation magnetization of 50 emu/g.