Origin of Photocatalytic Activation of Silver Orthophosphate from First-Principles

First-principles density functional theory incorporating the LDA + U formalism has been used to investigate the origin of photocatalytic activation of Ag3PO4. The approach provides an improved band gap and the position of the valence band if both U-p and U-d are used. Through examining the energy band structure and density of states we can understand why Ag3PO4 is a promising photocatalyst for oxidizing water as well as degrading organic contaminants., The results show that Ag3PO4 has a large dispersion of conduction band and the inductive effect of PO43-, which MP the separation of electron-hole pairs. It is demonstrated theoretically that Ag vacancies in Ag3PO4 with high concentration have a significant effect on the separation of electron-hole pairs and optical absorbance in the visible-light region. These findings present a reasonable explanation of recent experimental results.