Formation of hierarchical 2D/2D BP/MnxCd1-xS heterojunction boosting efficient photocatalytic hydrogen evolution

Photocatalytic water splitting for hydrogen production is an ideal green and energy-efficient strategy. However, due to severe recombination of photogenerated electron-hole pairs, and sluggish kinetics of the hydrogen evolution reaction (HER) on the catalyst surface, the current photocatalytic hydrogen production efficiency still fails to achieve satisfactory results. Therefore, in this study, a two-dimensional/two-dimensional (2D/2D) heterojunction BPM (BP/Mn x Cd 1-x S) was constructed via electrostatic self-assembly. The prepared 1 % BPM exhibited excellent photocatalytic hydrogen production performance (55.8 mmol g −1  h −1 ), demonstrating a two-fold improvement in hydrogen evolution performance compared to the MCS-7 solid solution. Comparative analysis of results from multiple characterization techniques revealed that the high-efficiency photocatalytic hydrogen production performance of BPM originates from the introduction of black phosphorus (BP) and the formation of the 2D/2D heterojunction: BP acts as a co-catalyst to inhibit the recombination of photogenerated electrons, while the heterojunction structure effectively separates charges, enabling efficient generation and utilization of photogenerated carriers. This study clarifies the role of BPM in photocatalytic water splitting, aiming to achieve efficient photocatalytic hydrogen production.