Au LSPR Effect Enhanced R‐CeO 2 /G‐C 3 N 4 S‐scheme Heterojunction for Accelerating CO 2 Photoreduction Performance

ABSTRACT Excellent CO 2 adsorption ability and fast photogenerated carriers’ supply are vital conditions for efficient CO 2 photoreduction. In this paper, Au localized surface plasmon resonance (LSPR) has been successfully applied in a R‐CeO 2 /g‐C 3 N 4 S‐scheme heterojunction photocatalyst for CO 2 photoreduction. R‐CeO 2 /Au/g‐C 3 N 4 (CAC‐2) exhibited excellent CO 2 photoreduction performance and great stability. The CO yield over CAC‐2 is about 50.58 µmol·g −1 ·h −1 under UV–vis light irradiation, which is about 6.7 and 6.0 times higher than that of R‐CeO 2 and g‐C 3 N 4 , respectively. FDTD simulation, DFT calculation and photoelectrochemical tests together prove the introduction of Au NPs not only enhances the photogenerated carriers’ separation efficiency, but also decreases the formation energy barrier of the important intermediate *COOH, which is beneficial for the CO 2 photoreduction to CO. N 2 /CO 2 adsorption‐desorption curves indicated that the CAC‐2 ternary composite had the largest specific surface area and the best CO 2 adsorption capacity. Meanwhile, DFT calculation confirmed that the reduction sites of the CAC‐2 had the highest electron density, which can synergistically enhance the CO 2 photoreduction activity. The improvement of photocatalytic performance can be attributed to the synergistic enhancement of Au LSPR effect and S‐scheme heterojunction at the interface. Based on the in situ FTIR, in situ ESR, and 13 C isotope tracer experiment, a potential LSPR effect‐enhanced S‐scheme heterojunction catalytic mechanism has been provided, which may represent a significant advancement in the field.