First principles study of the Ag nanoclusters adsorption effect on the photocatalytic properties of AgBr(110) surface

The electronic structures and photocatalytic performance of Ag-n/AgBr(110)(n = 7-13) are studied using density functional theory (DFT). The adsorption of Ag-n (n = 7-13) nanoclusters on AgBr(110) surface induces a new metal-induced gap band (MIGB) located between the valence band (VB) and the conduction band (CB), the variety of the electronic characters of AgBr(110) favor the visible and infrared light absorption, which improves the sunlight utilization. The dominant localization of the photo-excited electrons on the Ag-n clusters of Ag-n/AgBr(110)(n = 7-13) facilitates the oxidation-reduction reactions occurring on the surface and also effectively reduces the photolysis of AgBr under the sunlight irradiation. The overpotentials of the CB and VB edges indicate that photocatalytic conversion of CO2 with H2O to methanol is possible on AgBr(110) deposited with the Ag-n nanoclusters, which has been realized experimentally (An et al., 2012). The substantial strengthening of visible and infrared light absorption and the free energy profiles for the conversion of CO2 with H2O to methanol indicate that Ag-13/AgBr(110) surface can be expected to be the excellent photocatalysts. (C) 2018 Elsevier B.V. All rights reserved.