Solvent Engineering and Metal-Doping Dual Effects Enable Morphology Precise Controlled MOF-based Electrocatalysts for Highly Efficient Oxygen Evolution Reaction.

Designing economically viable electrocatalysts with superior activity for the oxygen evolution reaction (OER) represents a critical challenge in advancing practical water electrolysis systems for renewable hydrogen generation. In this work, CoFe-MOF(W) with a layered structure is created through synergistic modulation of a dual-regulation mechanism combining solvent engineering with metal doping, exhibiting superior electrocatalytic performance, requiring merely 276 mV overpotential to reach a current density of 10 mA cm while demonstrating fast kinetics with a 55 mV dec Tafel slope. The experimental results indicated that the solvent engineering facilitated the inducing unsaturated coordination states that tailored morphology and exposed more active sites, meanwhile, Fe-doping modulated the electronic structure of Co sites while introducing multimetal synergy for enhanced charge transfer, resulting in superior OER performance. Further mechanistic studies revealed that CoFe-MOF(W) underwent surface reconstruction, generating Co(Fe)OOH is the true OER active species. Moreover, the density-functional theory (DFT) calculations confirmed that Fe doping optimized OH adsorption free energy, thus enhancing the OER kinetics. This work elucidates a new insight into solvent modulation and metal doping strategies for MOF-based electrocatalysts to achieve efficient OER performance, which is potentially promising for applications in sustainable energy systems.