C–Co Nanocomposite Materials

The formation of cobalt particles on the surface of graphite supports via salt thermolysis is studied by x-ray diffraction, electron microscopy, Auger electron spectroscopy, and secondary ion mass spectrometry. The results demonstrate that each step in the fabrication of graphite–cobalt composites causes changes in the particle size, phase composition, and morphology of the deposit. The process involves the formation of a thin, fine-grained salt film on the surface of thermally expanded graphite particles as a result of impregnation; thermal decomposition of the salt, leading to the formation of crystalline cobalt oxide particles 50 to 100 nm in size, uniformly distributed over the surface of thermally expanded graphite; and the formation of Co particles on the graphite surface. The Co particles are 60–70 to 150 nm in size and form aggregates up to 400 nm in size.