Mechanism of Superior Visible-Light Photocatalytic Activity and Stability of Hybrid Ag3PO4/Graphene Nanocomposite

摘要

Electronic structure and photocatalytic performance of Ag3PO4(100) surface interfaced with graphene (GR) have been investigated using density functional theory. The interactions between GR and Ag3PO4(100) surface would induce the charge distribution fluctuations of GR sheet. A large built-in potential formed at the interface can prompt charge transfer from Ag3PO4 into GR in the ground electronic state, thus improving the stability of the hybrid Ag3PO4(100)/GR Due to C 2p states forming the upper part of valence band, the band gap is reduced to about 0.53 eV, resulting in a strong absorption in the entire visible region and thus superior photocatalytic activity. An absorption peak located near 440 nm in the calculated absorption spectrum can be rationalized by the experimental results of electron spin resonance. These results provide theoretical evidence supporting the experimental findings and pave the way for the applications of Ag3PO4-based nanocomposites.