Logo image
DFT Study of Antimony(V) Oxyanion Adsorption on α-Al2O3(11̅02)
Journal article   Peer reviewed

DFT Study of Antimony(V) Oxyanion Adsorption on α-Al2O3(11̅02)

Sai Kumar Ramadugu and Sara E Mason
Journal of physical chemistry. C, Vol.119(32), pp.18149-18159
07/14/2015
DOI: 10.1021/acs.jpcc.5b02061

View Online

Abstract

Density functional theory (DFT) calculations using periodic slab models are carried out to study the reactivity of aqueous Sb(OH)6– on model α-Al2O3(11̅02) surfaces. The strength of inner-sphere (specific) adsorption between Sb(OH)6– and surface models is ranked using DFT adsorption energies, Eads. Trends in Eads in terms of surface structure, adsorbing functional group identity, and oxyanion coordination to the surface are determined and analyzed in terms of geometry and electronic structure. The results show that not all Sb–Osurf interactions involve the same type of Sb and O orbital interactions, which explains why trends in Eads cannot be rationalized by universal Sb–O bond length–bond strength relationships. The DFT results show a preference for Sb(V) bidentate and tridentate geometries in which Sb bonds through the corners of AlO6 groups in the surface. Less favorable adsorption involving edge sites is associated with adsorption-induced surface relaxations of oxygen groups from deeper layers of the surface.

Details

Metrics

Logo image