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

摘要

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.