Bimetal-organic framework MIL-53(Co-Fe): an efficient and robust electrocatalyst for the oxygen evolution reaction.

Rationally designing high-efficiency catalysts for the oxygen evolution reaction (OER) is extremely important for developing sustainable energy technologies, but remains a major research challenge. In this paper, a Co/Fe-imidazole-based bimetal-organic framework nanosheet array grown on a nickel foam [MIL-53(Co-Fe)/NF] was prepared via a facile solvothermal process. Surprisingly, MIL-53(Co-Fe)/NF shows excellent OER activity with overpotential as low as 262 mV at 100 mA cm-2, much lower than those of the single metal-based MOFs, and even comparable to that of the precious RuO2. The results indicate that the synergetic effect of co-doped Fe and Co makes a crucial contribution to the high activity of the bimetal-based MOF catalyst. Additionally, this catalyst also displays outstanding long-term electrochemical durability for at least 80 h.