Constructed black phosphorus quantum dots/BiVO4 Z-scheme heterojunction catalysis for efficient Rhodamine b degradation and DFT study

Black phosphorus (BP) is highly regarded in photocatalysis for its bandgap thickness dependency, high hole mobility, and broad visible light absorption. This study introduces a simple hydrothermal method to construct a BP QDs/BiVO₄ direct Z-scheme heterojunction. The composite’s crystal structure, morphology, and photochemical properties were comprehensively characterized. The photocatalytic activity was evaluated using Rhodamine B (RhB) degradation under visible light. Notably, BP QDs_0.12%/BiVO₄ exhibited exceptional performance, achieving a 95.4 % RhB degradation after 100 min, three times higher than BiVO₄ alone. The direct Z-scheme heterojunction played a pivotal role in facilitating O₂⁻ and h⁺ involvement in the degradation process. The interfacial interaction between BP QDs and BiVO₄ significantly enhanced BiVO₄′s visible light absorption, preserving its strong oxidation–reduction capacity. This enhancement was further corroborated by DFT simulation calculations. Overall, this study presents a novel approach for constructing efficient Z-scheme photocatalysts based on BP QDs, laying a solid foundation for their application in the field of photocatalytic degradation.