Cobalt-based transition metal boride electrocatalysts for alkaline water oxidation reactions

The oxygen evolution reaction (OER) has an essential function in a multitude of renewable energy storage and conversion devices, and it is crucial to investigate efficient, stable, and cost-effective catalysts. Here, CoFeB nanosheets had been synthesized by a facile chemical reduction and in situ hydrolysis strategy. Nanosheet structure provided an abundance of active sites, which in turn facilitated mass transfer and electron transfer. Meanwhile, the formation of the highly oxidized state Co 3+δ is promoted by electron-deficient boron, which reduces the low onset potential, stimulates the activity of oxygen evolution, and enhances the kinetics of the OER. The overpotential was 390 mV and the Tafel slope was 66.35 mV dec −1 at a current density of 10 mA cm −2 in alkaline media. In addition, the electrocatalyst has exhibited long-term stability toward oxygen evolution and excellent catalytic activity. This research has further paved the way for the development of potentially novel and efficient OER electrocatalysts.