A QUANTUM-MECHANICAL STUDY OF THE (110) SURFACE OF SPHALERITE (ZNS) AND ITS INTERACTION WITH PB2+ SPECIES

Abstract

The structure of the (110) surface of sphalerite has been studied using mainly quantum-mechanical (QM) methods. The experimentally observed puckering of the surface is well reproduced by periodic plane wave density functional calculations. Water adsorption on this surface is modelled using this QM approach and is used to judge the accuracy of less computationally demanding cluster methods. A cluster model, thus validated, is used to study the possible modes of interaction of Pb2+ ions with the (110) surface. It is found that adsorption of hydrated PbO and PbOH+ is energetically feasible and leads to Pb–O distances compatible with REFLEXAFS data.