Comparative Study on Surface Structure, Electronic Properties of Sulfide and Oxide Minerals: A First-Principles Perspective

Abstract

First-principle calculations were used to investigate the surface structure and electronic properties of sulfide (pyrite, galena, and sphalerite) and oxide minerals (hematite, cerussite, and smithsonite). Surface relaxation and Femi energy, as well as projected DOS, are considered. Results show that the surface atoms of the sulfide minerals are more susceptible and more easily affected by the fracture bonds. The sulfide surfaces possess higher chemical potential than the corresponding oxide surfaces, and are more likely to be electron donors in reactions. The S 3p states are the mainly contributing states in the sulfide surface, while that in the oxide surface are O 2p states. The bonds of the sulfide surface have more covalent features and that of the oxide surface are ionic interactions. The O-M (M represents Fe, Pb or Zn) bonds are more stable, as the DOS of the oxide surfaces distribute in the lower energy range.

Prediction of Structural and Electronic Properties of C and Cl2 Adsorbed on the Rutile TiO2 (110) Surface

“…Generalized gradient approximation–Perdew–Burke–Ernzerhof (GGA-PBE) was used in the calculation of the exchange-correlation functional. − Figure shows the optimized structure of the TiO 2 (110) surface, and the surface contains Ti5c (fivefold coordinated Ti atom), Ti6c (sixfold coordinated Ti atom), O2c (twofold coordinated O atom), and O3c (threefold coordinated Ti atom). The calculation model adopted a 2 × 2 supercell, which was composed of nine atomic layers.…”