Fe and P dual-doped nickel carbonate hydroxide/carbon nanotube hybrid electrocatalysts for an efficient oxygen evolution reaction

Abstract

Designing cost-effective and highly active oxygen evolution reaction (OER) electrocatalysts is critical for large-scale hydrogen production from electrocatalytic water splitting. Herein, Fe and P dual-doped nickel carbonate hydroxide/carbon nanotubes (Fe, P–NiCH/CNTs) were fabricated through a solvothermal method. By virtue of the optimized electronic structure, improved conductivity and enriched active sites, the as-fabricated Fe, P–NiCH/CNT hybrid electrocatalyst exhibits superior OER activity, with a low overpotential of 222 mV at 20 mA cm⁻² and robust durability, confirming its potential as a highly efficient OER electrocatalyst. Moreover, theoretical calculations demonstrate that the doped Fe and surface adsorbed PO₄³⁻ can regulate the electronic structure of evolved NiOOH and decrease the energy barrier of the rate-determining step, thus leading to improved OER activity. The strategy presented in this work can also be employed to fabricate other transition metal carbonate hydroxides for various electrocatalytic applications.