In situ growth of Fe and Nb co-doped β-Ni(OH)2 nanosheet arrays on nickel foam for an efficient oxygen evolution reaction

Abstract

Developing highly efficient, Earth-abundant, and long-term stable electrocatalysts for the oxygen evolution reaction (OER) is of great importance for realizing industrial hydrogen generation from water splitting. Herein, a series of novel Fe and Nb co-doped β-Ni(OH)₂ nanosheet arrays were successfully grown in situ on Ni foam via a chlorine etching method. The representative NiFe₃Nb₂-OH displayed outstanding OER performance with an overpotential of 294 mV to deliver 100 mA cm⁻² in an alkaline electrolyte, outperforming other Ni related electrocatalysts. NiFe₃Nb₂-OH exhibited a stability of 90 h without obvious potential change at 50 mA cm⁻². Significantly, the doped Fe and Nb effectively enhanced the electrochemical active area and electronic transfer capability of β-Ni(OH)₂. Density functional theory (DFT) calculations indicated that the Gibbs free energy of the OER intermediates on the Fe, Nb co-doped β-Ni(OH)₂ electrode was optimized. The tuned electronic interactions between Fe, Nb and Ni apparently boosted the OER performance of NiFe₃Nb₂-OH. These results demonstrated that Fe and Nb co-doped β-Ni(OH)₂ is a highly efficient OER electrocatalyst in alkaline media.