Modulating Electronic Structures of Bimetallic Co-Fe Sulfide Ultrathin Nanosheet Supported on g-CN Promoting Electrocatalytic Hydrogen Evolution Performance.

Heteroatom doping is a possible way to regulate the catalytic capability of electrocatalysts for hydrogen evolution reaction (HER). This work focuses on the development of bimetallic Cobalt-Iron sulfide ultrathin nanosheets supported on the graphitic carbon nitride (g-CN) catalyst as efficient HER electrocatalysts (CoS/FeS/CN) with good stability at wide pH value. The ultrathin nanosheet exposes more active sites and enhances the catalyst activity. Electrochemical experiments demonstrate that adding g-CN and Fe to CoS increases its catalytic activity and stability. Furthermore, g-CN and Fe co-doped with CoS can modulate electronic structures on the interface. The CoS/FeS/CN exhibits outstanding HER performance, reaching a current density of 10 mA cm with overpotentials of only 76.5 mV in an acidic solution and 175.6 mV in an alkaline solution. It also demonstrates exceptional durability, superior to commercial platinum/carbon catalysts. This work introduces a promising approach for designing low-cost, high-performance HER electrocatalysts with a wide pH range.