Facile synthesis of multi-shelled ZnS-CdS cages with enhanced photoelectrochemical performance for solar energy conversion

• Main Authors: Zhang, Peng, Guan, Bu Yuan, Yu, Le, Lou, David Xiong Wen
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Chemical engineering; Solar Energy Conversion; Water Splitting
• Online Access: https://hdl.handle.net/10356/140076
• Institution: Nanyang Technological University

Constructing heterojunctions and designing advanced structures are effective approaches to enhancing the photoelectrochemical performance of semiconductor photocatalysts for solar energy conversion. Here, we have developed a sequential chemical etching, sulfidation, and cation-exchange strategy for preparing multi-shelled ZnS-CdS rhombic dodecahedral cages (RDCs) with tunable compositions and shell numbers from 1 to 5. Yolk-shelled Zn-based zeolitic imidazolate (ZIF-8) RDCs are first synthesized by chemical etching of ZIF-8 rhombic dodecahedrons. Sulfidation of the yolk-shelled ZIF-8 RDCs leads to the formation of multi-shelled ZnS RDCs, which are further converted into multi-shelled ZnS-CdS RDCs via a cation-exchange reaction. The composition of the multi-shelled ZnS-CdS RDCs can be tuned by varying the cation-exchange reaction time, and the shell number can be adjusted by changing the size of ZIF-8 precursors. Because of the heterojunction formed and the unique hollow structure, these triple-shelled ZnS-CdS RDCs with optimized composition show enhanced photoelectrochemical performance for solar water splitting.