Black Phosphorus Quantum Dots Modified CdS Nanowires with Efficient Charge Separation for Enhanced Photocatalytic H2 Evolution

Abstract Constructing a high‐quality interface with strong coupling interaction is highly desirable in composite photocatalysts for the efficient interfacial charge transfer. Herein, we prepared black phosphorus quantum dots/CdS (BPQDs/CdS) binary composites with tight interfacial contact via a facile electrostatic self‐assembly approach for efficient photocatalytic H 2 evolution. The optimized H 2 evolution rate of 3 wt % BPQDs/CdS can reach up to 9.9 mmol g −1 h −1 in lactic acid aqueous solution, 99 and 5.5 times greater than that of pristine BPQDs and CdS, respectively. Benefiting from the strong interface interaction between CdS and BPQDs in well‐contacted BPQDs/CdS composites, efficient charge separation can be achieved, leading to enhanced photocatalytic H 2 evolution activity. Notably, the rapid transfer of photogenerated electrons from CdS to BPQDs was unambiguously confirmed by time‐resolved transient absorption spectroscopy.