Bi-intercalation of H₂SO₄ into stages 4–6 FeCl₃–graphite intercalation compounds

Abstract

Stages 4–6 FeCl₃–graphite intercalation compounds (GIC’s) have been prepared by an ordinary two-bulb method, and the bi-intercalation processes of H₂SO₄ into the GIC’s have been studied by x-ray diffraction. Since stages 4–6 FeCl₃–GIC’s have more than three vacant interlayer spaces in the c-axis repeat distance, the bi-intercalation of H₂SO₄ into the GIC’s takes place stepwise. Consequently, various FeCl₃–H₂SO₄–graphite bi-intercalation compounds (GBC’s), from the GBC’s with one H₂SO₄ layer to the GBC’s saturated with H₂SO₄, are obtained in the bi-intercalation processes. Their compositions are described as C_6.0nFeCl₃ · c(6.0/6.5)H₂SO₄ from the calculation of structure factor for x-ray diffraction, where n is the stage number of the starting FeCl₃-GIC’s, and c is the number of H₂SO₄ layers. Stacking sequences of all the FeCl₃–H₂SO₄–GBC’s are also determined.