Cu1.94S-ZnS-CdS ternary heteronanoplates with efficient carrier transfer for enhanced photocatalytic hydrogen evolution

Abstract

Incorporating precise morphology control and efficient carrier separation into single-nanoparticle heterojunctions to achieve high photocatalytic efficiency remains a significant challenge. Here, we synthesized Cu1.94S-ZnS-CdS ternary heteronanoplates (HNPs) with a continuous sublattice structure using cation exchange reactions. Femtosecond transient absorption spectroscopy (TAS) confirms that ternary heterojunction enhances carrier separation efficiency, demonstrating both rapid separation (∼0.2 ps) and an extended lifetime (∼1512 ps). The synergistic combination results in a significantly enhanced hydrogen evolution rate of 2.012 mmol·g−1·h−1, which is 17 times and 183 times higher than that achieved by pure CdS and ZnS, respectively. Furthermore, there is no significant decrease in the activity of Cu1.94S-ZnS-CdS in photocatalytic hydrogen evolution after 288 days of placement. Our work offers an alternative approach for designing noble-metal-free photocatalysts with precisely defined materials and interfaces, aiming to enhance both photocatalytic hydrogen evolution efficiency and stability.