Heterostructured CoSe2/FeSe2 Nanoparticles with Abundant Vacancies and Strong Electronic Coupling Supported on Carbon Nanorods for Oxygen Evolution Electrocatalysis

Metal selenides attract great research interest as oxygen evolution reaction (OER) electrocatalysts. Herein, we report heterostructured bimetallic cobalt–iron diselenide nanoparticles with abundant vacancies and strong electronic coupling supported on carbon nanorod (CoSe2/FeSe2@C) as a highly efficient OER electrocatalyst. It is synthesized with a facile templating-engaged synthetic strategy and exhibits outstanding OER catalytic performance including high activity and good durability in alkaline medium. It affords a current density of 10 mA cm–2 at a low overpotential of 291 mV with small Tafel slope of 62 mV dec–1, which significantly outperforms the benchmarking RuO2 catalyst. The outstanding OER performance is found to be arising from its integrated advantages of the modulated electronic structure, abundant active sites, high electric conductivity, and large surface area endowed by its unique heterostructure and composition. This work exemplifies a feasible route to designing heterogeneous nanomaterials and enriches the OER electrocatalytic application of transition metal selenide-based hybrid materials.