A high efficient graphitic-C₃N₄/BiOI/graphene oxide ternary nanocomposite heterostructured photocatalyst with graphene oxide as electron transport buffer material

Abstract

It is important to reduce the recombination of electrons and holes and enhance charge transfer through fine controlled interfaces for advanced catalyst design. In this work, graphene oxide (GO) was composited with graphitic-C3N4 (g-C3N4) and BiOI forming GO/g-C3N4 and GO/BiOI heterostructural interfaces, respectively. GO, which has a work function between the conducting bands of g-C3N4 and BiOI, is used as a buffer material to enhance electron transfer from g-C3N4 to BiOI through the GO/g-C3N4 and GO/BiOI interfaces. The increased photocurrent and reduced photoluminescence indicate efficient reduction of electron and hole recombination under the successful heterostructure design. Accordingly, the introduction of GO as a charge transfer buffer material has largely enhanced the photocatalytic performance of the composite. Thus, introducing charge transfer buffer materials for photocatalytic performance enhancement has proved to be a new strategy for advanced photocatalyst design.

Enhanced visible light-driven photocatalytic performance of ZnO–g-C3N4 coupled with graphene oxide as a novel ternary nanocomposite

“…-0.5 and ca. -1.3 eV versus NHE, respectively [6,50]. Thus, g-C 3 N 4 absorbs light and transfers an electron from its VB to its CB.…”

“…The excited electrons then migrate to the CB of ZnO, while the positive holes in the VB of ZnO were transferred to the VB of g-C 3 N 4 , reducing recombination [51,52]. Notably, in the presence of GO, the photoinduced electrons in the ZnO CB migrate to GO as the work function of GO (-4.42 eV vs Vacuum and -0.08 eV 14 vs NHE) is lower than that of the work function of ZnO (-4.05 eV vs Vacuum and -0.5 eV vs NHE) [50][51][52][53][54], and the GO serves as an acceptor of electrons and suppresses charge recombination effectively. The charge carriers subsequently migrate to the composite surface, producing hydroxyl and superoxide radicals with water and dissolved oxygen, respectively, which can then proceed to oxidize MB [31].…”

“…The mechanism has been discussed based on the work function of g-C 3 N 4 , ZnO, and GO as reviewer suggested. The modified mechanism is included in the text [50][51][52][53][54], and the GO serves as an acceptor of electrons and suppresses charge recombination effectively.…”

Facile synthesis of Z-scheme graphitic-C3N4/Bi2MoO6 nanocomposite for enhanced visible photocatalytic properties

“…A deconvolution core level spectrum at about 284.76 and 288.38 eV has been presented. The major peak at 284.76 eV is exclusively assigned to carbon atoms (C-C bonding) in a pure carbon environment, i.e., graphitic or amorphous carbons either in our sample or adsorbed to the surface [41]. The peak at 288.38 eV is identified as originating from carbon atoms bonded to three nitrogen atoms in the g-C 3 N 4 lattice [42].…”

g-C3N4 decorated ZnO nanorod arrays for enhanced photoelectrocatalytic performance

“…the X values for ZnO and g-C 3 N 4 are about 5.95 and 4.72 eV [46,47], the E VB of ZnO and g-C 3 N 4 are calculated to be 3.03 and 1.58 eV vs. NHE (Normal Hydrogen Electrode), respectively. Moreover, the E CB of ZnO and g-C 3 N 4 are estimated to be -0.13 and -1.13 eV vs. NHE.…”