In Situ Mn-Doping-Promoted Conversion of Co(OH)₂ to Co₃O₄ as an Active Electrocatalyst for Oxygen Evolution Reaction

Abstract

Revealing the intrinsic catalytic properties and their dependence on other factors is always a desired challenge in the field of catalysis. Finding and fine-tuning of the inherent electrocatalytic properties of 3D nonprecious metal hydroxides and oxides by a foreign element doping is an attractive domain in the electrocatalysis of water oxidation. This report reveals such an effect of Mn doping on the electrocatalytic oxygen evolution reaction (OER) of Co3O4 nanosheet arrays grown on nickel foam (NF) by the ammonia evaporation technique. The Mn doping induces the in situ conversion of Co(OH)2 into Co3O4 during deposition. The strain generation during doping and the presence of metallic Mn are important factors for enhanced OER performance. Such a unique way of doping as well as in situ conversion of hydroxides into oxides offer an excellent electrocatalyst with superior performance compared to pristine Co3O4 or Co(OH)2 nanoflakes.