Crystal Structure Regulation of CoSe Induced by Fe Dopant for Promoted Surface Reconstitution toward Energetic Oxygen Evolution Reaction.

Most nonoxide catalysts based on transition metal elements will inevitably change their primitive phases under anodic oxidation conditions in alkaline media. Establishing a relationship between the bulk phase and surface evolution is imperative to reveal the intrinsic catalytic active sites. In this work, it is demonstrated that the introduction of Fe facilitates the phase transition of orthorhombic CoSe into its cubic counterpart and then accelerates the Co-Fe hydroxide layer generation on the surface during electrocatalytic oxygen evolution reaction (OER).