Engineering Ni2P-NiSe2 heterostructure interface for highly efficient alkaline hydrogen evolution

Developing earth-abundant transition-metal phosphides electrocatalysts with high activity and good durability toward alkaline hydrogen evolution reaction (HER) is crucial for sustainable hydrogen energy economy. However, their intrinsic activity is limited by the inadequate hydrogen adsorption energy. Herein, we reported a novel self-supported heterostructure catalyst in the form of Ni 2 P-NiSe 2 , which is obtained by phosphorization of NiSe 2 nanosheet arrays grown on the carbon cloth. The heterostructure catalyst exhibits excellent HER performance in 1 M KOH, only requiring an overpotential of 66 mV at a current density of 10 mA cm −2 with a Tafel slope of 72.6 mV dec -1 and showing excellent long-term durability. The experimental and theoretical calculation results demonstrate the strongly electronic interaction between Ni 2 P and NiSe 2 , resulting in the optimized Gibbs free energy of hydrogen and water adsorption. This work concerning the regulation of electronic structure through interface engineering may offer a deep insight to explore superior catalysts.