In Situ Growth of NiFe MOF/NF by Controlling Solvent Mixtures as Efficient Electrocatalyst in Oxygen Evolution

Abstract Two-dimensional metal-organic frame (2D MOF) materials have attracted great attention due to the successful combination of the unique properties of MOF and chemical properties of 2D material. In this paper, NiFe MOF/NF with a two-dimensional layered vertical structure were prepared by bottom-up solvothermal method. We used different solvent mixtures (methanol/water, ethanol/water, acetone/water, N, N-dimethylformamide/water) to control the synthesis of MOF and found that the oligpolar solvent mixture of acetone and water was the best in controlling the formation of these two-dimensional MOFs. The obtained NiFe MOF/NF in acetone/water appeared the best performance as electrocatalyst for the oxygen evolution reaction, in which the NiFe MOF/NF delivered a current density of 50 mA·cm-2 at a low overpotential of 270 mV with a small Tafel slope of 55mV·dec-1. In addition, NiFe MOF/NF has an excellent stability at a high current density of 100 mA·cm-2.