An XPS study of binding energies of sulphur in carbon

Abstract X-ray photoelectron spectroscopy was used to measure binding energies of S 2p electrons of sulphur in S-trithiane, and in anisotropic carbon (heat-treatment temperature 873 K) formed from S-trithiane and from a humic acid derived from a Polish brown coal. A satisfactory technique is to prepare the specimens as a thin film on a gold plate. In all these materials, the sulphur atom environments are identical, corresponding to heterocyclic sulphur, 163.3 eV binding energy. Experimental binding energies are compared with those obtained using a charge-potential model from CNDO orbital calculations.