Three-dimensional self-supporting Ni2P-Ni12P5/NF heterostructure as an efficient electrocatalyst to enhance hydrogen evolution reaction

Increasing active sites by constructing a heterostructure is a very effective method to improve the electrocatalytic performance. In this work, we synthesized a three-dimensional self-supporting Ni 2 P-Ni 12 P 5 /NF heterostructure supported on nickel foams by hydrothermal reaction and low-temperature phosphorization, used as an efficient hydrogen evolution reaction (HER) electrocatalyst. The structure, composition, morphology, and HER performance of the catalyst were characterized by XRD, XPS, SEM, TEM, and electrochemical workstation. The experimental results show that the Ni 2 P-Ni 12 P 5 /NF heterostructure demonstrates better HER catalytic activity in 0.5 M H 2 SO 4 , only requiring an overpotential of 124 mV at 10 mA cm −2 with a Tafel slope of 84.1 mV dec −1 and displaying good long-term stability. The high activity and stability of the as-synthesized Ni 2 P-Ni 12 P 5 /NF catalyst in HER are mainly due to the synergy between Ni 2 P-Ni 12 P 5 with a unique heterostructure and nickel foam conductive substrate with a three-dimensional porous structure, which is beneficial to increase the electrocatalytic active area and thus provide more active sites.