Ultrathin Fe-MOFs modified by FeS for highly efficient oxygen evolution reaction.

Developing efficient and economical catalysts is essential for water splitting. The application of MOF catalysts in water splitting is limited by poor conductivity; however, the introduction of conductive TMS could enhance their activity. Herein, novel composite FeS/Fe-MOF/NF-2 was constructed by introducing dendritic FeS onto the surface of a 2D ultrathin Fe-MOF. Composite catalysts elaborately utilize the structural and chemical advantages of MOF and TMS while improving the deficiencies of monomers through the combination. Owing to the optimal structure, the hybrid catalyst FeS/Fe-MOF/NF-2 displayed better catalytic performance than bare Fe-MOFs and FeS, with low overpotentials of 202 and 216 mV at 10 mA cm in alkaline solution and simulated seawater, respectively. This work provides an innovative approach to modify MOFs as electrocatalysts for OER.