Enhanced photocatalytic CO2 conversion over 0D/2D CsPbBr3/BiOCl S-scheme heterojunction via boosting charge separation

The stable contact of heterogeneous interfaces and the substantial exposure of active sites are crucial for enhancing the photocatalytic performance of semiconductor catalysts. However, most reported two-dimensional (2D)/2D CsPbBr3 and BiOCl heterostructures are fabricated using electrostatic self-assembly methods, which exhibit significant deficiencies in precise interface quality control and effective active site exposure. In this study, we fabricate a zero-dimensional (0D)/2D CsPbBr3/BiOCl heterojunction via a two-step calcination method, achieving an efficient direct S-scheme configuration. Optimizing interfacial contact and band alignment between CsPbBr3 quantum dots and BiOCl nanosheets enhances cross-plane charge transfer, promoting superior charge separation. This 0D/2D CsPbBr3/BiOCl heterojunction exhibits enhanced carrier mobility and high conversion rates without cocatalysts or sacrificial agents. The mechanism underlying the accelerated S-scheme charge transfer is comprehensively elucidated through a combination of analytical techniques and density functional theory (DFT) calculations. This study offers a novel approach for managing charge carrier segregation and mobility in CO2 reduction photocatalysts.