LAUSR

Surface self-reconstruction by the electrochemical activation is considered as an effective strategy to increase the oxygen evolution reaction (OER) performance of transition metal compounds. Herein, uniform Co2(OH)3Cl microspheres are developed and present an activation-enhanced OER performance caused by the etching of lattice Cl- after 500 cyclic voltammetry (CV) cycles. Furthermore, the OER activity of Co2(OH)3Cl can be further enhanced after small amounts of Fe modification (Fe2+ as precursor). Fe doping into Co2(OH)3Cl lattices can make the etching of surface lattice Cl- easier and generate more surface vacancies to absorb oxygen species. Meanwhile, small amounts of Fe modification can result in a moderate surface oxygen adsorption affinity, facilitating the activation of intermediate oxygen species. Consequently, the 10% Fe-Co2(OH)3Cl exhibits a superior OER activity with a lower overpotential of 273 mV at 10 mA cm-2 (after 500 CV cycles) along with an excellent stability as compared with commercial RuO2.