Heterogeneous bimetallic sulfides based seawater electrolysis towards stable industrial-level large current density

Abstract

Direct seawater electrolysis is an attractive technology for scalable hydrogen production as well as seawater desalination, which however demands efficient and robust anodic catalysts that can sustain oxygen evolution reaction (OER) against chloride corrosion. Here we report an outstanding anodic catalyst consisting of three-dimensional standing arrays of hetero-lateral Ni3S2/Co3S4 (NiCoS) nanosheets uniformly grown on Ni foam for alkaline seawater electrolysis, in which the in-situ derived Ni/Co (oxy)hydroxide surface layer endows abundant active sites and superior resistance to chloride corrosion. Combined with an efficient hydrogen evolution reaction catalyst of Ni/Mo sulfides, a two-electrode electrolyzer affords an industrial-level high current density up to 800 mA cm−2 at a super low voltage of 2.08 V for overall alkaline seawater splitting steadily over 100 h without chloride corrosion at room temperature. Furthermore, powered by a commercial single III-V triple-junction solar cell, the integrated system demonstrates light-driven overall seawater splitting with an impressive 15.13 % solar-to-hydrogen efficiency. This work is instrumental in the development of seawater electrolysis for sustainable hydrogen production by renewable energy sources.