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

Abstract

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.

Insights into Enhanced Visible-Light Photocatalytic Hydrogen Evolution of g-C3N4and Highly Reduced Graphene Oxide Composite: The Role of Oxygen

“…For all the composites, a potential well is formed between RGO(GR) and g-C 3 N 4 layer, which is similar with that at the Ag 3 PO 4 (100)/GR interface. 53 During the photocatalytic process, the photogenerated electrons in the RGO-3(4) layer can be easily driven to the CB of the g-C 3 N 4 layer due to the CBO, while the holes in the g-C 3 N 4 layer to the VB of the RGO-3(4) layer. Therefore, the existence of potential well can effectively hinder the recombination of photogenerated charge carriers in the g-C 3 N 4 /RGO composites.…”

Graphene-wrapped Ag 3 PO 4 /LaCO 3 OH heterostructures for water purification under visible light

“…The photocatalytic response of this novel Ag 3 PO 4 photocatalyst is dozens of times faster than that of commercial TiO 2-x N x [13]. Unfortunately, the low structural stability and large crystallite size of Ag 3 PO 4 (0.5-2 µm) have remained major hindrances, limiting its photocatalytic performance and large scale practical applications [14].…”

Electronic Structures and Photocatalytic Responses of SrTiO3(100) Surface Interfaced with Graphene, Reduced Graphene Oxide, and Graphane: Surface Termination Effect

“…many semiconductors (for examples, TiO 2 , CeO 2 , g-C 3 N 4 ) with wide band gap, the incorporated GR(RGO) sheet can extend their absorption edge to vis-light region [33][34][35]. The significantly enhanced photocatalytic activity of the STO/GR composite has only been experimentally demonstrated 30 under UV irradiation.…”