Silver Silicates with Three-Dimensional d10-d10 Interactions as Visible Light Active Photocatalysts for Water Oxidation

Abstract: Ag2SiO3 and Ag9(SiO4)2NO3 with the short Ag？Ag bond distances close to metallic Ag have optical band gaps of 2.6？eV and 2.0？eV, respectively. They oxidized water molecules to oxygen with the rates of 98 and 194？μmol/g？·？h by the 280？mW/cm2 visible-light illumination, and decolorized organic dye more than 10 times faster than the commercialized WO3 and TiO2. Based on the electronic structure calculation, their small band gaps and superior carrier transport property are correlated with the spatial proximity between Ag ions stabilized by d10-d10 interaction, which promotes the descent and dispersion of conduction bands by increasing Ag 5s/5p orbital overlaps.