Surface proximity effect of galena and its influence on synergistic adsorption behavior

Abstract The proximity effect induced by the adsorption of butyl xanthate on the galena (1 0 0) surface and its influence with other butyl xanthate and methyl xanthate have been investigated based on DFT method. The finding shows that the bidentate coordination of butyl xanthate on the galena (1 0 0) surface can cause perturbations of the surrounding atoms. The Pb atoms on the surface are more sensitive than that of the S atoms, and their movements along the z-axis are much greater than the latter atoms; besides, the relaxation of the Pb atoms and single-S atoms decreases with the adsorption distance. The surface atomic charges are also redistributed after the adsorption of butyl xanthate, and the potential energy of Pb atoms increases with the closer distance of the adsorption site, i.e., Pb2 atoms are more stable than Pb3 and Pb4 atoms. Further studies prove that the adsorbed butyl xanthate ligand does have an effect on the re-adsorption of neighboring Pb atoms, and the Pb2 atoms are more obvious than the Pb3 atoms.