2D iron-doped nickel MOF nanosheets grown on nickel foam for highly efficient oxygen evolution reaction

Abstract

Recently, metal–organic framework (MOF) manifests an outstanding oxygen evolution reaction (OER) catalytic activity due to its structural diversity, highly ordered pore structure and abundant active sites. Herein, through a facile one-step solvothermal method, iron-doped nickel MOF nanosheets in situ grown on conductive nickel foam (Fe-Ni MOF NSs/NF) were conveniently fabricated as efficient OER catalyst, using only one kind of metal salt precursor. The ultrathin 2-dimensional sheet structure possesses highly exposed surface area and numerous metal sites which are beneficial to electrocatalytic OER performance. The Fe-Ni MOF NSs/NF presents superior OER activity in 1 M KOH, requiring overpotentials of 258 and 270 mV to deliver the current density of 50 and 100 mA cm−2, along with a low Tafel slope of 40.8 mV dec−1. Moreover, the durability of the Fe-Ni MOF NSs/NF catalyst is also outstanding, exhibiting only minor chronoamperometric decay after 24 h continuous operation at 50 mA cm−2. The excellent OER activity could be ascribed to the coupling effects of ultrathin-nanosheet structure, favorable charge transfer kinetics, high conductivity and excellent intrinsic catalytic activity. This facile and economical strategy might be advantageous to prepare other high-performance MOF-based OER catalysts.