Bi₄O₅Br₂/CeO₂ Composite with S-scheme Heterojunction: Construction and CO₂ Reduction Performance

One of the basic challenges of CO2 photoreduction is to develop efficient photocatalysts. As an effective strategy, constructing heterostructure photocatalysts with intimate interfaces can enhance interfacial charge transfer for realizing high photocatalytic activity. Herein, a novel photocatalytic material, Bi4O5Br2/CeO2 composite fiber (B@C-x, x refers to the amount of reactant), was constructed by embeding CeO2 nanofibers on Bi4O5Br2 nanosheets via an electrospinning combined with hydrothermal method. Its composition, morphology and photoelectric properties were characterized. The results show that Bi4O5Br2/CeO2 heterojunction with appropriate Bi4O5Br2 content can significantly improve the photocatalytic performance of CeO2 nanofibers. Compared with pure Bi4O5Br2 and CeO2, B@C-2 exhibited the best photocatalytic activity under simulated sunlight. The Bi4O5Br2/CeO2 exhibited improved photocatalytic CO2 reduction performance with a CO generation rate of 8.26 mu mol center dot h(-1)center dot g(-1) without using any sacrificial agents or noble co-catalysts. This can be attributed to the tight interfacial bonding between Bi4O5Br2 and CeO2 and the formation of S-scheme heterojunction, which enables the efficient spatial separation and transfer of photogenerated carriers. This work provides a simple and efficient method for directional synthesis of Bi-based photocatalytic composites with S-scheme heterojunction and illustrates an applicable tactic to develop potent photocatalysts for clean energy conversion.