Novel heterostructure Cu(2)S/Ni(3)S(2) coral-like nanoarrays on Ni foam to enhance hydrogen evolution reaction in alkaline media

Exploring efficient alternatives to precious noble metal catalysts is a challenge. Here, a new type of non-noble metal Cu(2)S/Ni(3)S(2) heterostructure nanosheet array is fabricated on 3D Ni foam. This electrocatalyst has excellent activity and durability to Hydrogen Evolution Reaction (HER) under alkaline conditions. The synergistic catalysis produced by the {2̄10} and (034) crystal planes and the increase in charge transfer and the number of active sites caused by lattice defects greatly improve the electrocatalytic activity of Ni(3)S(2). In the HER process, the Cu(2)S/Ni(3)S(2) interface increases the formation of S–H bonds, and Cu(2)S promotes the transformation during the HER process into S-doped CuO, optimizing the adsorption capacity of S-doped sites for H. Among electrocatalysts made with different feed ratios, Cu(2)S/Ni(3)S(2)/NF-3, for HER, only needs an overpotential of 50 mV to deliver a current density of 10 mA cm(−2). This work provides a promising non-noble metal electrocatalyst for water splitting under alkaline conditions.