Tracking the structural evolution and activity origin of Co-doped NiFe layered double hydroxide for enhanced oxygen evolution reaction

Development non-precious electrocatalysts in oxygen evolution reactions (OER) with excellent activity and durability is of great significance but challenging for electrochemical water splitting. Herein, under the guidance of theoretical calculation, we report that in-situ Co-doped NiFe (NiFeCo) LDH is an excellent catalyst for oxygen evolution reaction (OER), and its activity and durability are superior to NiFe layered double hydroxide (LDH). The dynamic evolution of its structure/composition is uncovered by in-situ Raman and UV–vis spectroscopies, in which Co doping reduces the Ni oxidation potential and accelerates the formation of highly active Ni(Co)_1-xFe_xOOH species during OER. The reconstructed product catalyzes the OER with low overpotential of 261 and 318 mV at 100 and 500 mA cm⁻², respectively, and maintains outstanding stability for at least 300 h at 500 mA cm⁻² in 1.0 M KOH. Our findings not only deepen the basic understanding of the OER process of this material, but also provide theoretical basis and practical guidance for the further development of new low-cost electrocatalysts.