Constructed Z-Scheme g-C3N4/Ag3VO4/rGO Photocatalysts with Multi-interfacial Electron-Transfer Paths for High Photoreduction of CO2

Abstract

Z-scheme g-C₃N₄/Ag₃VO₄/reduced graphene oxide (rGO) photocatalysts with multi-interfacial electron-transfer paths enhancing CO₂ photoreduction under UV–vis light irradiation were successfully prepared by a hydrothermal process. Transmission electron microscope images displayed that the prepared photocatalysts have a unique 2D–0D–2D ternary sandwich structure. Photoelectrochemical characterizations including TPR, electrochemical impedance spectroscopy, photoluminescence, and linear sweep voltammetry explained that the multi-interfacial structure effectively improved the separation and transmission capabilities of photogenerated carriers. Electron spin resonance spectroscopy and band position analysis proved that the electron-transfer mode of g-C₃N₄/Ag₃VO₄ meets the Z-scheme mechanism. The introduction of rGO provided more electron-transfer paths for the photocatalysts and enhanced the stability of Ag-based semiconductors. In addition, the π–π conjugation effect between g-C₃N₄ and rGO further improved the generation and separation efficiency of photogenerated electron–hole pairs. Then, the multiple channels (Ag₃VO₄ → CN, Ag₃VO₄ → rGO → CN, and rGO → CN) due to the 2D–0D–2D structure greatly improving the photocatalytic CO₂ reduction ability have been discussed in detail.