Fabrication of Hexagonal Prism-Shaped Double S-Scheme Cu<sub>2</sub>O@CdS/ZnS Heterojunctions Utilizing Zeolite Templates: Enhanced Photocatalytic Hydrogen Production and Mechanism Insight
Jing Li, Dingze Lu, Kiran Kumar Kondamareddy, Wenju Gu, Yucheng Liu, Yaoheng Su, Zhanghai You, Huiqing Fan, Wingkei Ho
Abstract
The production of photocatalytic hydrogen through water splitting is a promising green route due to its nontoxicity and harmlessness, but a key challenge lies in improving the separation efficiency of photogenerated charge carriers. To address this issue, we have successfully synthesized a hexagonal prism-shaped double S-scheme Cu 2 O@CdS/ZnS heterojunction, utilizing a microporous zeolite as a sacrificial template. This unique structure exhibits a remarkable enhancement in charge carrier separation and transfer capabilities, enabling highly efficient photocatalysis. Specifically, the best photocurrent responses were observed in the 420–450 nm wavelength range. Notably, the hexagonal prism-shaped double S-scheme Cu 2 O@CdS/ZnS heterojunction exhibits an excellent photocatalytic hydrogen production performance (8.30 mmol·h –1 ·g –1 ), which is nearly 10 times higher than that of pure CdS and 1.2 times higher than that of CdS/ZnS. To further elucidate the mechanism behind this enhanced hydrogen production, we propose a hydrogen production pathway for Cu 2 O@CdS/ZnS, supported by density functional theory (DFT) calculations. The improved performance of hydrogen production can be attributed to the synergistic effect of the double S-scheme heterojunctions and the hexagonal prism-shaped structure, which collectively accelerate the photogenerated charge transport efficiency and enhance the hydrogen production efficiency.