Efficient water oxidation using flower-like multiphase nickel hydroxide with Fe doping

Abstract

Ingeniously designing a water-oxidation catalyst with advantages of a large surface area, multicomponent synergy, and optimized electronic structure, especially utilizing a one-step reaction system to achieve these dominant characteristics is pivotal to high-performance electrochemical water splitting. Here, flower-like multiphase nickel hydroxide catalysts doped with Fe (Fe-α,β-Ni(OH)₂) are fabricated through a one-pot solvothermal-coordination methodology. The resulting Fe-α,β-Ni(OH)₂ presents excellent oxygen production activity. An overpotential of 267 mV is required to drive a current density of 30 mA cm⁻². Fe-α,β-Ni(OH)₂ achieves stable operation for over 20 h. The considerable OER performance should result from the unique bionic flower structure, large surface area, and Fe-doping as well as the unique phase interfaces between the α- and β-Ni(OH)₂ components. Our study provides a new trial of combining several favorable structural features into one material system that benefits efficient OER catalysis based on earth-abundant Fe and Ni elements.