Graphitic carbon nitride/La, Rh co‐doped SrTiO 3 S‐scheme heterojunction for photocatalytic CO 2 reduction

Abstract Photocatalytic reduction of CO 2 has attracted considerable interest owing to its potential to resolve the energy and environmental problems. Nevertheless, the lack of proficient photocatalysts has restricted the application of solar‐driven photocatalytic CO 2 reduction. Herein, we reported an S‐scheme heterojunction by combining g‐C 3 N 4 with La 3+ and Rh 3+ co‐doped SrTiO 3 through the electrostatic self‐assembly method for the efficient photocatalytic CO 2 reduction. In comparison with g‐C 3 N 4 , the as‐prepared CN/LRSTO‐30 wt% S‐scheme heterojunction not only possesses a broadened visible‐light response due to the defect states in La, Rh co‐doped SrTiO 3 induced by co‐doped La 3+ and Rh 3+ but also has more adsorption sites for the capture and activation of CO 2 molecules. Additionally, separation and transfer efficiency of the photoinduced charge carriers is much enhanced in the CN/LRSTO‐30 wt% S‐scheme heterojunction via its robust internal electric field, which is firmly demonstrated by in situ irradiation X‐ray photoelectron spectroscopy technology. Consequently, the prepared S‐scheme heterojunction achieves impressive photocatalytic CO 2 reduction performance with an average CO and CH 4 evolution rate of 4.1–1.8 μmol·g −1 ·h −1 , respectively, which are ~ 1.9 and ~ 22.5‐fold higher than those of pure g‐C 3 N 4 . This study provides innovative perspectives on the design of creative S‐scheme heterojunctions for applications in photocatalytic CO 2 reduction.