DFT+U Study of Arsenate Adsorption on FeOOH Surfaces: Evidence for Competing Binding Mechanisms

Otte, Katrin; Schmahl, Wolfgang W. und Pentcheva, Rossitza (2013): DFT+U Study of Arsenate Adsorption on FeOOH Surfaces: Evidence for Competing Binding Mechanisms. In: Journal of Physical Chemistry C, Vol. 117, No. 30: pp. 15571-15582

Abstract

On the basis of periodic density functional theory (DFT) calculationsincluding an on-site Coulomb repulsion term U, we study the adsorptionmechanism of arsenate on the goethite (101), akaganeite (100), andlepidocrocite (010) surfaces. Mono- and bidentate binding configurationsof arsenate complexes are considered at two distinct iron surfacesites-directly at 5-fold coordinated Fe1 and/or 4-fold coordinated Fe2as well as involving ligand exchange. The results obtained within abinitio thermodynamics shed light on the ongoing controversy on thearsenate adsorption configuration, and we identify monodentate adsorbedarsenate complexes as stable configurations at ambient conditions with astrong preference for protonated arsenate complexes: a monodentate

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science
• Subjects: 500 Science > 530 Physics; 500 Science > 540 Chemistry; 500 Science > 550 Earth sciences and geology
• Language: English