Theoretical study of high photocatalytic performance of Ag3PO4

The recent discovery of an excellent photocatalyst, Ag3PO4, motivated us to clarify the origin of its high performance. Our comprehensive study using density-functional-theory-based calculations has revealed that the formation of PO4 tetrahedral units with strong P-O bonds weakens the covalent nature of Ag-O bonds, inhibiting hybridization of Ag d and O p. This excludes the d character from the conduction-band minimum (CBM), leaving highly dispersive Ag s-Ag s hybrid bands. The delocalized charge distribution of the CBM results in a small effective mass of the electron, which is advantageous for the carrier transfer to surface.