Hierarchical sulphide - phosphide NiSP /NF catalyst prepared by gradient electrodeposition for oxygen evolution reaction

Abstract

Rational design and fabrication of electrocatalysts with low-cost and high efficiency is highly desired. In this paper, a hierarchical honey-comb catalyst NiSP supported on nickel foam (NF) was synthesized by a facile gradient electrodeposition method. Attributed to the presence of Ni2P and NiS and the synergistic effect among phosphide and sulphide, NiSP /NF catalyst exhibited a low overpotential value of 281 mV to achieve 10 mA cm−2 and the Tafel value of 68.51 mV dec−1 in 1 M KOH. Benefited from the gradient electrodeposition process resulting in the nanoparticles decorate honey-comb structure, the electrochemical active surface area reaches to 3571.5 cm2, and the turnover frequency (TOF) value is 2.0781 s−1. Due to the good electric conductivity of phosphide and sulphide, NiSP /NF electrode kept to exhibit excellent stability for 60 h. Therefore, the electrode obtained by our gradient electrodeposition method was expected to be a promising candidate catalyst.