Photothermal Conversion Boosted Photocatalytic CO2 Reduction over S-Scheme CeO2@Cu-TCPP: In Situ Experiments and DFT Calculations

Herein, interfacial and defect-engineering strategies synergistically promote photocatalytic properties. Because of the matching energy levels and the close interfacial contact, the CeO2@Cu-TCPP S-scheme architecture is successfully constructed via the in situ wet chemistry route. Photothermal conversion assists abundant OVs on the CeO2 compartment. Strong evidence of an S-scheme charge transfer path is verified by density functional theory (DFT) calculations and in situ irradiated X-ray photoelectron spectroscopy (XPS). This S-scheme heterojunction system is more deep-seated in facilitating the separation and transfer of photogenerated carriers as well as acquiring strong photoredox ability. Meanwhile, the abundant OVs proved by XPS and electron paramagnetic resonance spectra (ESR) enhanced the light-harvesting capacity and conductivity and shortened the transfer route. As a result, this synergistic heterojunction could mostly promote photocatalytic CO2 activation. The typical 0.25CeO2@ Cu-NS exhibited the best photocatalytic CO2RR to form CO and CH4 (rate: 229.6 μmol·g–1), which is even 45.8- and 1.5-folds higher than those of pristine LA-CeO2 (5.0 μmol·g–1) and Cu-TCPP (152.2 μmol·g–1), respectively, higher than those of other reported CeO2-based photocatalysts. This study presents a reinforcement and matrix prospect for domain charge behaviors to accelerate CO2 activation.