Mn0.05Cd0.95S decorated MOF-derived Co9S8 hollow polyhedron for efficient photocatalytic hydrogen evolution

The photocatalytic hydrogen evolution reaction is one of the important ways to convert solar energy into renewable hydrogen. In this work, the Co9S8 hollow polyhedron was formed after sulfidation and calcination with the metal-organic framework ZIF-67. The hollow polyhedron Co9S8 provides abundant support sites for Mn0.05Cd0.95S and effectively reduces the agglomeration degree of Mn0.05Cd0.95S. The Co9S8 hollow polyhedron as the reaction site has a large specific surface area and a mesoporous structure, which is beneficial to the progress of the photocatalytic reaction. A series of tests showed that the introduction of Co9S8 hollow polyhedron significantly improved the light-trapping ability and exposed more reaction sites. Co9S8 hollow polyhedrons are used as electron capture sites, which can effectively collect electrons and induce the interface charge transfer of Mn0.05Cd0.95S to Co9S8. Because the Co9S8-Mn0.05Cd0.95S composite catalyst had a strong light-trapping ability, abundant reaction sites and Co9S8-Mn0.05Cd0.95S heterojunction accelerate the separation and transfer of charges. Therefore, the hydrogen evolution rate of the 10%Co9S8-Mn0.05Cd0.95S composite catalyst was relatively high, which was 13.369 mmol g(-1) h(-1). In addition, the 10%Co9S8-Mn0.05Cd0.95S composite catalyst still has good hydrogen evolution stability after four cycles. This research may supply a new idea for the preparation of high-efficiency photocatalysts with hollow structures.

Automated summary

The Co9S8 hollow polyhedron was successfully prepared by sulfidation and calcination of the metal-organic framework ZIF-67, providing abundant support sites for Mn0.05Cd0.95S and enhancing the catalytic activity. The introduction of Co9S8 hollow polyhedron significantly improved light-trapping ability and exposed more reaction sites, leading to enhanced photocatalytic performance.