Improving the oxygen evolution performance of iron-manganese oxyhydroxides by Cr doping

The slow oxygen evolution reaction (OER) dynamics affect the energy efficiency of many electrocatalytic reactions. To accelerate the commercialization of electrolytic water, efficient and economical OER electrocatalysts need to be developed. Here, a series of FeMnMOOH/NF (M = Cr, Ni, Co, Cu, Zn, Sc and Ru) oxyhydroxides are constructed by a hydrothermal method and Cr doping illustrates the optimum oxygen evolution activity with a low overpotential of 241 mV. Cr doping increases the active sites, prevents Fe leaching, accelerates charge transfer, and lowers the energy barrier, thus promoting the OER. In situ Raman spectra indicate that Fe, Mn and Cr sites are all involved in the OER and the cooperative mechanism among them accelerates the reaction.