Investigations of exfoliating graphite intercalation compounds using time-resolved DEXAFS

Abstract
The exfoliation processes (rapid thermal decomposition) of CuCl₂ graphite intercalation compounds (GICs) cointercalated with FeCl₃ or AlCl₃ were investigated using time resolved X-ray absorption spectroscopy in an energy dispersive mode. The experiments were carried out at the DEXAFS beam line at HASYLAB (Hamburg). The evolution of the absorption spectra of the Cu K-edge was compared with the reaction of pure CuCl₂ under the same conditions. From the exfoliation of the CuCl₂/AlCl₃-GIC a CuO graphite compound can be obtained. The formation resembles the reaction of pure CuCl₂, whereas the exfoliation of the CuCl₂/FeCl₃-GIC results in a mixture of Cu₂O, CuO and Cu clusters. The reduction of the Cu(II) at a reaction temperature of 500°C is correlated with an oxidation of Fe(II) to Fe(III).