Vertically aligned ReS2 on MOF deorived CoS2–C hybrid as core-shell catalyst for promoting overall water splitting

The rational design of a core-shell structured electrocatalyst is important to improve the efficiency of electrocatalytic hydrogen production through water splitting. Herein, the catalyst is composed of rhenium disulfides (ReS2) vertically grown on cobalt sulfides/carbon hybrid by hydrothermal and activation treatment (CoS2–C@ReS2/CFP). The core-shell structure is constructed by sulfurizing the cobalt-based metal-organic framework, preventing the restacking of the ReS2 nanosheet, exposing more active sites, and facilitate electrolyte ion diffusion. Moreover, the CoS2–C@ReS2/CFP catalyst shows exceptional performance during the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) process in an alkaline electrolyte. At ·10 mA cm−2, the overpotentials of the CoS2–C@ReS2/CFP catalyst are 85 and 257 mV during the HER and OER processes with the small Tafel slope, low charge transfer resistance and exceptional catalytic stability. The combination of the CoS2 core and ReS2 shell is designed to adjust the adsorption energy of water molecules, promoting water dissociation, and enhancing the catalytic activity of CoS2–C@ReS2/CFP catalyst. This work provides an efficient strategy for developing the core-shell structured catalysts, potentially advancing the practical application into water splitting for hydrogen production.