Nanosized NiFeSe2/NiCo2O4 hierarchical arrays on Ni foam as an advanced electrocatalyst for hydrogen generation

The rational design of composite catalysts is critically essential for electrochemical water splitting. Here, we report on a novel hierarchical composite that comprises NiFeSe2 nanoparticles and NiCo2O4 nanoflakes supported on nickel foam (NF) as an efficient electrocatalyst for the hydrogen evolution reaction (HER). The conjunction of the NiFeSe2 nanoparticles and NiCo2O4 nanoflakes introduces a new synergistic effect for the HER, resulting in an improved NiCo2O4 catalyst. The as-prepared NiFeSe2/NiCo2O4/NF electrode exhibited an enhanced HER activity, with a low overpotential of 83 mV at a current density of 10 mA cm(-2), a low Tafel slope of 45 mV dec(-1), and an excellent long-term electrochemical stability in alkaline media. This hierarchical architecture is instrumental in exposing the catalytically active sites, boosting mass transport, and speeding up the release of generated hydrogen bubbles from the electrode surface. This research offers a promising way for the electrocatalytic performance of the catalysts toward large-scale water splitting.