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Indexed by:Journal Papers

Date of Publication:2020-02-01

Journal:ADVANCED ENERGY MATERIALS

Included Journals:EI、SCIE

Volume:10

Issue:5

ISSN No.:1614-6832

Key Words:electrocatalysis; in situ transformation; vacancies; water oxidation

Abstract:Electrocatalytic water splitting for hydrogen generation is hindered by the sluggish kinetics of water oxidation, and highly efficient electrocatalysts for the oxygen evolution reaction (OER) are urgently required. Numerous bi- and multimetal-based, low-cost, high-performance OER electrocatalysts have been developed. However, unary metal-based high-performance electrocatalysts are seldom reported. In the present study, Co-2(OH)(3)Cl/vanadium oxide (VOy) composites are synthesized, from which VOy is completely etched out by a simple cyclic voltammetry treatment, which simultaneously transforms Co-2(OH)(3)Cl in situ to ultrafine CoOOH. The selective removal of VOy modulates the nature of the surface in the obtained CoOOH by creating surface oxygen vacancies (V-o), along with disordered grain boundaries. The best-performing CoOOH with optimum V-o is found to be associated with a low overpotential of 282 mV at 10 mA cm(-2) catalytic current density on a simple glassy carbon electrode for OER. This facile protocol of selectively etching VOy to modulate the nature of the surface is successfully applied to synthesize another Fe-based electrocatalyst with high OER performance, thus establishing its utility for unary metal-based electrocatalyst synthesis.