Black Phosphorus Quantum Dots Modified CdS Nanowires with Efficient Charge Separation for Enhanced Photocatalytic H-2 Evolution

摘要

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.