Metal-oxygen bonding nanoarchitectonics for regulation of oxygen evolution reaction performance in FeNi-codoped CoOOH.

Bimetallic doping is widely used to enhance the oxygen evolution reaction (OER) activity of layered transition metal oxyhydroxides. However, the synergistic enhancement effect of different doping elements on the intrinsic OER activity is still obscure. In this study, the FeNi-codoped cobalt oxyhydroxide (CoOOH) as OER electrocatalyst was prepared successfully by simple electrodeposition and anodic oxidation methods, which exhibits superior OER activity to the single-metal doped CoOOH systems. Based on both experiments and first-principles calculations, the results show that the reaction kinetics enhance due to the codoping of Fe and Ni. Fe-doping changes the active site from Co to Fe and enhances the hydroxyl group adsorption. Ni doping benefits the electron transfer between Fe and intermediates, thereby enhancing the Fe–O covalent component to further balance the two steps of hydroxyl group adsorption and the deprotonation step. The essential mechanism of bimetal-doping in CoOOH provides theoretical support for the design and development of bimetal-doped Co-based OER catalysts. [Display omitted] • The FeNi-codoped CoOOH as OER electrocatalyst is prepared successfully, which has high OER activity and good stability. • Fe doping decreases the adsorption energies of intermediates and benefits adsorption between Fe and intermediates. • The increased covalent components between active sites and intermediates after Ni doping result in the enhanced OER activity. [ABSTRACT FROM AUTHOR]