Three-dimensional coral-like cobalt selenide as an advanced electrocatalyst for highly efficient oxygen evolution reaction

Oxygen evolution reaction (OER) influences some important renewable energy technologies such as water splitting. Although many OER electrocatalysts have been studied to surmount this difficult problem, the development of a highly active, inexpensive and sustained OER electrocatalyst is still a great challenge. In this study, we report a novel, cost-effective cobalt selenide (coral-like CoSe) electrocatalyst with high current density (∼97.5 mA cm−2 at 1.606 V vs. RHE) and strong durability in alkaline media. The chronoamperometric response of coral-like CoSe electrocatalyst can remain 98% of its initial current density after 10000 s at the overpotential of 350 mV in 1 M KOH. The prepared coral-like CoSe electrode exhibits a low overpotential of 295 mV at a current density of 10 mA cm−2 and a small Tafel slope of 40 mV dec−1, which exceeds previously reported state-of-art RuO2 electrocatalyst and is much better than CoSe nanoparticles (CoSe NPs) and precursor Co(OH)2 electrocatalysts. This work affords us a 3D Co-based electrocatalyst with high performance and strong durability under alkaline conditions, which can be applied to energy conversion and storage processes.