DFT study on the interaction between hydrogen sulfide ions and cerussite (110) surface

The interaction between hydrogen sulfide ions ( HS-) and the cerussite surface was simulated using density functional theory ( DFT) calculations. The calculated results show that Pb atoms are the dominating active sites for the subsequent reaction on the cerussite ( 110) surface. The S atom in HS- ions can readily interact with the Pb atoms at the cerussite surface layers with the interaction energy of -5.19 eV, resulting in the formation of lead sulfide species. An obvious difference occurs when HS- ions interact with the various Pb atoms on the cerussite surface. The density of state analysis reveals that the Pb 6p orbital at the mineral surface layers and S 3p orbital from HS- ions are overlapped between -1.5 and 0.5 eV near the Fermi level, indicating a stable chemical adsorption. The Mulliken population result suggests that the electron transfer exists between the bonding atoms and the oxidation of the HS- ions is involved in the adsorption process. This study provides an insight into the sulfidization mechanism at an atomic level, and further confirms the experimental phenomenon proposed in our previous work. (C) 2016 Elsevier B. V. All rights reserved.