Boosting electrocatalytic performance of CoFe hydroxide catalyst by P-doping for oxygen evolution

Abstract

Background

As one of the most favorable catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes, cobalt iron layered double hydroxide (CoFe LDH) stands out among the others. Yet its catalytic activity still needs improvement.

Methods

In this paper, doping of non-metallic elements is introduced to enhance its catalytic activity for OER. Using a one-step solvothermal method, P-doped CoFe layered double hydroxide (P-doped CoFe LDH) was synthesized and grown on nickel foam (NF).

Significant findings

P-doped CoFe LDH/NF exhibits superior catalytic activity for oxygen evolution relative to CoFe LDH/NF prepared using the same method. A high current density of 300 mA cm^-2 only requires an overpotential of 347 mV. Compared with CoFe LDH/NF (367 mV), this is dramatically smaller. XPS analyses indicate that the contents of Co³⁺ and Fe³⁺ high oxidation state species in P-doped CoFe LDH/NF are obviously higher than that in CoFe LDH/NF. Stability tests demonstrated P-doped CoFe LDH kept 72 h. And surfaces of P-doped CoFe LDH had interconnected porous two-dimensional nanosheet structures, which contributed to stable nature of the electrode. Our work provides the strategy of P doping to enhance OER performance for LDH-based electrocatalysts.