Fe/Ni Metal–Organic Frameworks and Their Binder-Free Thin Films for Efficient Oxygen Evolution with Low Overpotential

Multivariate metal–organic frameworks with active Fe/Ni building blocks that are spatially arranged in an open structure are synthesized and explored for oxygen evolution reaction. The heterogeneity and porosity of this system prove to show synergy effect and give low onset overpotential at 170 mV. These MOFs are further fabricated into thin films over nickel foam by controlled electrochemical deposition to improve the surface conductivity and the overall stability. The Fe/Ni metal–organic framework film exhibits outstanding electrocatalytic activity with low overpotential of 270 mV at 10 mA cm–2, small Tafel slope, high Faradaic efficiency, high turnover frequency, and great stability.