One-Pot-Synthesized CoFe-Glycerate Hollow Spheres with Rich Oxyhydroxides for Efficient Oxygen Evolution Reaction

Catalysts applied for oxygen evolution reaction (OER) are vital to bring future renewable energy systems and convert the water to oxygen and hydrogen fuel. Herein, we report that bimetal-glycerate hollow spheres organized by nanosheets (CoFeG-HS) can be first produced by the one-pot template-free method as an efficient OER electrocatalyst. According to the time-dependent experiments, the growing mechanism gets revealed, assigned to the Ostwald ripening process. Compared with the samples after they are annealed, the catalyst of CoFeG-HS shows greatly lower overpotential and enhanced kinetics for OER, with an overpotential of 242 mV at 10 mA·cm–2, and a Tafel slope of 49.4 mV·dec–1 because of the richness of oxyhydroxide-containing species on the surface of catalysts is helpful to the high performance of the OER. Based on the comparison with the Co-glycerate and Fe-glycerate, the CoFeG-HS with more highly active performance and cycled stability profits from the specific hollow structure, optimized composition on the surface, and interaction of Co2+ and Fe3+. The experiment of the catalyst with/without black carbon shows that the important role of black carbon is in reducing the electron transfer resistance to improve the activity. Thus, the currently developed CoFeG-HS with superior OER performance may potentially serve as a material for use in industrial alkaline water electrolyzers.