Poorly crystallized nickel hydroxide carbonate loading with Fe3+ ions as improved electrocatalysts for oxygen evolution

Oxygen evolution reaction is a critical process involved in various energy-related devices. In this study, nickel hydroxide carbonate nanosheets obtained through a urea assisted route were loaded with iron species by immersing nickel hydroxide carbonate in aqueous Fe3+ solution. The different Ksp values of nickel hydroxide and iron hydroxide induce the formation of Fe species on nickel hydroxide carbonate nanosheet surface with the releasing of Ni2+ ions. Owing to the loading of island-like Fe species on nickel based nanosheets, the thus designed and prepared composites show amounts of exposed heterointerfaces with strong interactions between the species, and so present excellent electrocatalytic activity for oxygen evolution. At a lower overpotential of 277 mV, the optimized catalyst can drive a current density of 10 mA cm−2 with higher stability. This study provides a new avenue for the development of OER electrocatalysts; that is, direct immersing with ion adsorption is effective.