Sea Urchin-Like ZnCdS/ZnS Nanocomposite for Photocatalytic H2 Evolution Under Visible Light

Abstract This work presents a strategy for designing a highly efficient catalyst by constructing heterojunctions and introducing a cocatalyst of Pd. A series of sea-urchin-like ZnCdS/ZnS (ZCS/ZnS) nanocomposites were prepared by a one-step solvothermal method under various input Zn/Cd ratios, and their visible-light-driven H2 production performances were explored. Moreover, cocatalyst Pd was introduced to further increase the photocatalytic activity. The photocatalytic reaction mechanism was explored by means of experimental results and density functional theory (DFT) calculations. The results show that the hydrogen evolution rate (HER) of the 10Pd-ZCS/ZnS-4 nanocomposite with the optimal input Zn/Cd ratio of 9:1 was the highest, 43.378 mmol g–1 h–1, which was 964 times that of the pure ZnS and 2 times that of the ZCS/ZnS-4. The excellent H2 production performance of 10Pd-ZCS/ZnS-4 could be mainly attributed to the higher charge transfer efficiency/separation and the lower activation energy for reactions due to the synergistic effect of Pd and ZnCdS–ZnS heterojunctions.