文摘
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 Up and Ud 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鈭?/sup>, which help the separation of electron鈭抙ole pairs. It is demonstrated theoretically that Ag vacancies in Ag3PO4 with high concentration have a significant effect on the separation of electron鈭抙ole pairs and optical absorbance in the visible-light region. These findings present a reasonable explanation of recent experimental results.