Nanostructured NiFe (oxy)hydroxide fabricated on nickel foams by laser-induced water plasma for enhanced alkaline oxygen evolution reaction

Abstract

Hydrogen production from water electrolysis is hindered by the sluggish reaction kinetics, especially the anodic oxygen evolution reaction (OER). Dynamic surface structures and high valence metal sites are usually required in the development of highly efficient OER electrocatalysts, which are hardly realized using conventional preparation method. Here, we propose a novel and facile method to fabricate nickel-based OER electrocatalysts with non-thermal laser-induced water plasma. Using nickel foams (NFs) as the initial substrates, the NFs or Fe-doped FeOx/NFs treated with laser-induced water plasma own abundant Ni(Fe) hydroxide and oxyhydroxide nanostructures,labeled as Ni(Fe) (oxy)hydroxide thereafter, formed on the skeleton of NFs, which are characterized in detail by SEM, TEM, XPS and Raman spectra. The as-prepared Ni(Fe) (oxy)hydroxide/NFs electrocatalysts show greatly enhanced OER activity and stability. The optimized NiFe (oxy)hydroxide/NFs bimetallic electrocatalysts achieve a current density of 10 mA cm−2 at the overpotential of only 268 mV with a small Tafel slope of 53.6 mV dec-1. During 28 h long term stability test at 10 mA cm−2, there is negligible increase in the required overpotential. These findings demonstrate that non-thermal laser-induced water plasma is a promising and efficient way to prepare highly efficient electrocatalysts with dynamic surface structures and high valence metal sites.