Enhanced interface interaction in Cu2S@Ni core-shell nanorod arrays as hydrogen evolution reaction electrode for alkaline seawater electrolysis.

Exploring cheap, efficient and stable electro-catalysts for hydrogen evolution reaction (HER) is a vital technology for seawater splitting development. Herein, we demonstrate that constructing underlying Cu 2 S nanorod arrays is crucial for improving the HER activity of surface Ni catalyst. Electrochemical results reveal that nickel coated Cu 2 S nanoarrays (Cu 2 S@Ni) on copper foam exhibits a preferable HER activity (~500 mA cm−2 at <200 mV overpotential), outperforming Cu 2 O@Ni and pure Ni counterparts. Detailed analyses indicate that the enhanced HER activity of Cu 2 S@Ni can be attributed to Ni–S interaction between surface nickel and underlying Cu 2 S nanorods, which optimizes the adsorption energy of hydrogen on the surface. Moreover, the Cu 2 S@Ni nanoarray electrode shows a remarkable HER stability, highlighting its promising potential in alkaline seawater electrolysis. • Enhanced HER performance by Ni–S interaction. • Core-shell Cu 2 S@Ni nanorod arrays for alkaline seawater. • Preferable HER activity: ~500 mA/cm2 at <200 mV overpotential. • Favorable durability in alkaline seawater for hydrogen evolution. • Optimization of hydrogen adsorption energy on nickel. [ABSTRACT FROM AUTHOR]