Self-Reconstruction of Fe-Doped Co-Metal-Organic Frameworks Boosted Electrocatalytic Performance for Oxygen Evolution Reaction.

Rational design of facile and low-cost efficient electrocatalysts for oxygen evolution reaction (OER) is crucial to solve the energy crisis. Benefiting from in situ self-reconstruction from metal-organic frameworks (MOFs) to (oxy)hydroxides in alkaline electrolytes, MOFs have become alternative OER catalysts. Thus, Fe-doped Co-MOF nanosheets (Co-MOF/Fe) were prepared and utilized straightforwardly as OER electrocatalysts. CoFe-layered bimetallic hydroxides (CoFe-LDHs) with abundant active sites are obtained from in situ conversion of Co-MOF/Fe after etching by the KOH electrolyte, which are generally actual active species. Meanwhile, the introduction of Fe ions will also produce a synergistic effect that greatly improves the electrocatalytic OER performance. The optimized catalyst (Co-MOF/Fe10) shows exceptional OER activity (η10 = 260 mV) and excellent durability over 50 h. The outstanding OER performance of Co-MOF/Fe10 can also be reflected in the two-electrode hydrolyzer (1.57 V at 10 mA cm-2). This study offers a pathway to probe the catalytic mechanism of MOFs and the rational construction of efficient MOF-derived catalysts.