A cobalt hydroxide coated metal-organic framework for enhanced water oxidation electrocatalysis

Although metal-organic frameworks (MOFs) with coordinatively unsaturated metal centers have been regarded as promising electrocatalysts towards oxygen evolution reaction (OER), few reports focus on MOFs with inactive coordinative-saturated metal centers. Herein, we report a universal strategy to generate a layer of Co(OH)(2) coating on the surface of Co-MOFs (Co(OH)(2)/Co-MOF) through an in situ cathodic electro- transformation approach. Experimental analysis and density functional theory (DFT) calculations reveal that electrons transfer from Co(OH)(2) to Co-MOF could synergistically tailor the adsorption free energy of oxygenic intermediates in the OER pathways, which together with the unique structure of Co-MOF, contribute to the outstanding OER performance and long-term stability, with overpotential of 196 mV to achieve the current density of 10 mA cm(-2).