Co-P bond effect on an MOF-derived CoS hollow polyhedron supported NiP co-catalyst for efficient photocatalytic hydrogen evolution

• Published in: Dalton transactions : an international journal of inorganic chemistry 2023-07, Vol.52 (28), p.9744-9756
• Main Authors: Wang, Yanxia, Hu, Xiude
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d3dt01553j

The development of new, efficient noble-metal-free photocatalysts is of great significance for the photocatalytic hydrogen evolution reaction. Herein, Co 9 S 8 with a hollow polyhedral structure was synthesized by in situ sulfurization of ZIF-67, and subsequently, Co 9 S 8 @Ni 2 P composite photocatalytic materials were prepared by loading Ni 2 P on the surface of Co 9 S 8 through a solvothermal method based on a morphology regulation strategy. The design of the 3D@0D spatial structure of Co 9 S 8 @Ni 2 P is favorable for the formation of photocatalytic hydrogen evolution active sites. Due to the excellent metal conductivity of Ni 2 P, Ni 2 P as a cocatalyst can accelerate the separation of photogenerated electrons from holes in Co 9 S 8 , thus providing a large number of available photogenerated electrons for photocatalytic reactions. It is worth mentioning that a Co-P chemical bond is formed between Co 9 S 8 and Ni 2 P, which plays an active role in the transport of photogenerated electrons. The densities of states of Co 9 S 8 and Ni 2 P were determined by density functional theory (DFT) calculations. The reduction of the hydrogen evolution overpotential and the formation of efficient charge-carrier transport channels on Co 9 S 8 @Ni 2 P were confirmed by a series of electrochemical and fluorescence tests. This study provides a new idea for the design of highly active noble-metal-free materials for the photocatalytic hydrogen evolution reaction. A novel and efficient Co 9 S 8 @Ni 2 P composite photocatalyst was successfully prepared by loading Ni 2 P on the surface of Co 9 S 8 , in which the formation of Co-P bonds accelerates electron migration and promotes photocatalytic reaction.