A Ni-MOF nanosheet array for efficient oxygen evolution electrocatalysis in alkaline media

Highly stable and efficient non-noble-metal electrocatalysts are strongly desired for the oxygen evolution reaction (OER) in alkaline media. In this study, we report the use of 4,4′-biphenyl dicarboxylic acid as an organic ligand to in situ develop an Ni-MOF nanosheet array on nickel foam (Ni-MOF/NF) as an OER catalyst. In 1 M KOH, such 3D Ni-MOF/NF drives a current density of 20 mA cm −2 at a low overpotential of 350 mV. Moreover, it exhibits strong long-term electrochemical stability for at least 24 h and achieves a high turnover frequency of 0.24 mol O 2 per s at an overpotential of 400 mV. Ni-MOF(bpdc) nanosheet array on nickel foam (Ni-MOF/NF) is a superior OER catalyst with a requirement of an overpotential of 350 mV to attain 20 mA cm −2 in 1.0 M KOH.