Accessible New Non-Quantum Dot Cs₂PbI₂Cl₂-Based Photocatalysts for Efficient Hole-Driven Photocatalytic Applications

Efficient, low-cost photocatalysts with mild synthesis conditions and stable photocatalytic behavior have always been the focus in the field of photocatalysis. This study proves that non-quantum-dot Cs₂PbI₂Cl₂-based materials, created by a simple method, can be successfully employed as new high-efficient photocatalysts. The results demonstrate that two-dimensional Cs₂PbI₂Cl₂ perovskite can achieve over three times higher photocatalytic performance compared to three-dimensional CsPbBr₃ perovskite. Moreover, the photocatalytic performance of Cs₂PbI₂Cl₂ can be further improved by constructing a heterojunction structure, such as Cs₂PbI₂Cl₂/CsPbBr₃. Cs₂PbI₂Cl₂ can connect well with CsPbBr₃ through a simple method, resulting in tight bonding at the interface and efficient carrier transfer. Cs₂PbI₂Cl₂/CsPbBr₃ exhibits notable 5-fold and 10-fold improvements in photocatalytic performance and rate compared to CsPbBr₃. Additionally, Cs₂PbI₂Cl₂/CsPbBr₃ demonstrates superb stable catalytic performance, with nearly no decrease in photocatalytic performance after 7 months (RH = 20% ± 10, T = 25 °C ± 5). This study also reveals that the photocatalytic process based on Cs₂PbI₂Cl₂/CsPbBr₃ can directly oxidize organic matter using holes, without relying on the generation of intermediate reactive oxygen species from water or oxygen (such as ·OH or ·O₂^-), showcasing further potential for achieving high photocatalytic efficiency and selectivity in anhydrous/anaerobic catalytic reactions and treating recalcitrant pollutants.