Porous cobalt sulfide nanosheets arrays with low valence copper incorporated for boosting alkaline hydrogen evolution via lattice engineering

Porous Cu-CoSx nanosheets arrays arranged on Ni foam (Cu-CoSx/NF) are constructed by a hydrothermal strategy assisted with sulfur vapor etching, which displays a high alkaline HER performance. The introduction of low valence copper induces the lattice contraction of CoSx, it not only brings the enrichment of electron cloud density to nearly Co active sites, but also optimizes the kinetics of hydrogen evolution and the adsorption behaviors of reactants, which promotes the catalytic performance of alkaline HER and Zn-H2O cell.