Carbon encapsulated mixed-metal sulfide as proficient electrocatalyst for hydrogen evolution reaction

Proficient electrocatalyst for hydrogen evolution reaction (HER) synthesized via a single-step, simple and low-temperature pyrolysis method. The mixed metal sulfide catalyst Co₉S₈/NiS@C shows irregular multi-shaped structure having small pores covered with carbon layers. The as-prepared Co₉S₈/NiS@C composites are made up of very small intermingled nanoparticles. The tiny nanoparticle contains large surface area that serves as an active-site for excellent HER performances. The Co₉S₈/NiS@C electrode is tested under alkaline solution performs overpotential (vs. RHE) of 0.28 V at current density of 10 mA cm⁻². It exhibits a low R_ct with an excellent and continuous stability for 10 h. The excellent HER performances of Co₉S₈/NiS@C are attributed to shape, size, and crystal structure of mixed metal sulfide and small surface pores that provide abundant active sites for electrocatalysis reaction.