Self-Supported CoSe₂ Nanorods for Efficient Oxygen Evolution and Urea Oxidation

It is important for the practical application of water electrolysis to explore stable and earth-rich bifunctional catalysts for oxygen evolution reaction (OER) and urea oxidation reaction (UOR). An immersion-selenization strategy was proposed to prepare CoSe2/Co nanorods anchored on Co foam as bifunctional catalysts for OER and UOR. Due to the self-supported properties of CoSe2/Co and its unique nanorod structure, the OER activity is enhanced, showing an overpotential of 318 mV and a Tafel slope of 91.11 mV dec–1. In addition, the electrode showed excellent electrocatalytic UOR activity with an overpotential of 260 mV and a Tafel slope of 94.83 mV dec–1. The nanorod structure was basically retained after a 28 h durability test. This work provides a broad approach to the development of low-cost bifunctional electrocatalysts.