Enhanced oxygen evolution activity on mesoporous cobalt–iron oxides

Abstract

To solve the energy crisis and environmental pollution problems, the use of clean and renewable energy to replace fossil energy has become a top priority. The oxygen evolution reaction (OER) is the core of many renewable energy technologies. Developing low-cost and high-performance OER electrocatalysts is the key to implementing efficient energy conversion processes. Here, we synthesize ordered mesoporous iron–cobalt oxides using a hard template strategy. As a mesoporous oxide catalyst, meso-CoFe_0.05O_x exhibits low OER overpotentials of 280 and 373 mV at current densities of 10 and 100 mA cm⁻², respectively, and does not show deactivation for at least 18 hours at 100 mA cm⁻². The introduction of iron can change the electronic structure of Co, and the orbital electrons are easily transferred from cobalt to iron. The enhanced OER performance can be attributed to concerted catalysis between the iron and cobalt sites that lowers the OER energy barrier, and the large specific surface area of the porous oxide providing efficient active sites for the reaction.