Bifunctional hierarchical NiCoP@FeNi LDH nanosheet array electrocatalyst for industrial-scale high-current-density water splitting

Abstract

Aiming to design and prepare non-noble metal electrocatalysts for hydrogen production at high current density (HCD), NiCoP@FeNi LDH hierarchical nanosheets were deposited on nickel foam progressively using a hydrothermal-phosphorization-electrodeposition process. For hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), NiCoP@FeNi LDH/NF requires only 195 and 230 mV overpotentials to reach 1000 mA cm−2, respectively. For overall water splitting, only 1.70 V is required at 1000 mA cm−2. This is the largest value for non-noble metal-based electrocatalysts reported so far at HCD. The hierarchical structure exhibits good electron transport capability and the porous-macroporous structure enhances the gas release rate, resulting in enhanced hydrogen production at HCD. Especially, the synergistic effect of NiCoP and FeNi LDH contributes to the adsorption-desorption equilibrium of intermediate radicals during the reaction process and ultimately enhances the catalytic activity. This work provides useful direction for industrial-scale hydrogen production applications at HCD.