In situ growth of FeCo sulfides on cobalt iron foam for efficient high-current-density hydrogen evolution reaction electrocatalysis.

Hydrogen, with its high energy density and environmental friendliness, represents an ideal alternative to traditional fossil fuels. The development of cost-effective electrocatalysts is crucial for achieving efficient hydrogen production through water splitting. In this study, a novel three-dimensional octahedral cubic CuS-CuS-CuS-CoS-CuFeS/CFF (FeCoCuS/CFF) electrocatalyst was synthesized via a facile two-step hydrothermal method using a unique Fe-Co alloy foam as the substrate. The catalyst demonstrated exceptional hydrogen evolution reaction (HER) performance, achieving an overpotential of only 272 mV at a high current density of 1000 mA cm and maintaining stability for over 100 h at 100 mA cm. Theoretical calculations indicate that the Co sites in CuS-CoS heterostructure exhibits the highest HER catalytic activity because of the G is near zero. These results indicate that the unique octahedral cubic architecture not only enriched heterogeneous structures but also facilitated gas adsorption, enhancing catalytic activity. This non-precious metal-based electrocatalyst, prepared through a hydrothermal approach, exhibits high catalytic activity and stability, showing promising potential for industrial applications in water electrolysis and as a viable alternative to precious metal-based electrocatalysts.