Abstract
Metal‐organic frameworks (MOFs) have been considered as potential oxygen evolution reaction (OER) electrocatalysts owning to their ultra‐thin structure, adjustable composition, high surface area, and high porosity. Here, we designed and fabricated a vanadium‐doped nickel organic framework (V1−x−NixMOF) system by using a facile two‐step solvothermal method on nickel foam (NF). The doping of vanadium remarkably elevates the OER activity of V1−x−NixMOF, thus demonstrating better performance than the corresponding single metallic Ni‐MOF, NiV‐MOF and RuO2 catalysts at high current density (>400 mA cm−2). V0.09−Ni0.91MOF/NF provides a low overpotential of 235 mV and a small Tafel slope of 30.3 mV dec−1 at a current density of 10 mA cm−2. More importantly, a water‐splitting device assembled with Pt/C/NF and V0.09−Ni0.91MOF/NF as cathode and anode yielded a cell voltage of 1.96 V@1000 mA cm−2, thereby outperforming the‐state‐of‐the‐art RuO2(+)||Pt/C(−). Our work sheds new insight on preparing stable, efficient OER electrocatalysts and a promising method for designing various MOF‐based materials.
The spherical structure V‐doped Ni‐MOF was successfully constructed on nickel foam by a facile two‐step hydrothermal method. The V0.09−Ni0.91MOF/NF catalyst demonstrates extraordinary OER performance in alkaline. Studies showed that the three‐dimensional structure of V‐doped Ni‐MOF/NF can provide more catalytically active sites and adjust the binding energy with intermediates, thereby enhancing the OER catalytic activity.