In Situ Growth of Sn‐Doped Ni3S2 Nanosheets on Ni Foam as High‐Performance Electrocatalyst for Hydrogen Evolution Reaction

Abstract Nickel sulfides have been widely employed as high‐performance electrocatalysts for the hydrogen evolution reaction (HER) with high activity and low cost, and their performance could be tremendously promoted by elaborate design. Herein, we report a simple solvothermal route for the in situ growth of a three‐dimensional network structure of Sn‐doped Ni 3 S 2 , assembled by using ultrathin nanosheets on Ni foam. The ultrathin nanosheets with thicknesses of approximately 5–9 nm could provide more exposed active edges and a shorter electron transfer path. The Sn‐doped sample exhibited efficient and durable electrocatalytic HER activity both in acid and alkaline conditions, much better than that of undoped Ni 3 S 2 nanorods. Nyquist plots indicated that the electrochemical impendence reduced with the introduction of elemental Sn, which was another critical factor for the enhanced catalytic performance.