Comparison of hydrothermal and electrodeposition methods for the synthesis of CoSe2/CeO2 nanocomposites as electrocatalysts toward oxygen evolution reaction

Abstract

Promoting efficacious and low-cost catalysts for the oxygen evolution reaction (OER), as the sluggish half-reaction of the water splitting, is inevitable to make sustainable energy technologies more promising. In this work, we report a series of novel nanocomposites comprising CeO2 nanorods decorated with CoSe2 nanoparticles. The nanocomposites were prepared via a conventional hydrothermal synthesis or a rapid electrodeposition process, and their structure, morphology, and electrochemical performance toward OER in alkaline solution were compared. To tune the electrocatalytic activity, the mass ratio of CoSe2 to CeO2 was systematically varied. Compared with the hydrothermal synthesis, the much faster electrodeposition method yielded a nanocomposite with a similar or slightly better performance in OER. This nanocomposite exhibited an overpotential of 290 mV (at 10 mA cm−2 current density), a Tafel slope of 53 mV dec−1, and excellent electrochemical stability for 15 h. Overall, these findings demonstrate the great potential of CoSe2/CeO2 nanocomposites as effective OER electrocatalysts for future applications.