Tuning the Electronic Structure of W 18 O 49 via Dual Doping for Efficient Oxygen Evolution Reaction

Doping is an effective approach to tune the structure of materials at an atomic level, optimizing their performance toward various energy conversion applications. Herein, we show that nickel (Ni) and iron (Fe) dual doping activates the electrochemical inert W 18 O 49 into a highly active electrocatalyst toward the oxygen evolution reaction (OER). Compared to monodoping, dual doping of Ni and Fe in the lattice of W 18 O 49 results in the synergistic modulation of the electronic structure and physicochemical properties of tungsten oxides. The Ni and Fe dual-doped W 18 O 49 (NiFe–W 18 O 49 ) achieves a low overpotential of 325 mV at a current density of 10 mA cm –2 and a Tafel slope of 42 mV dec –1 for the OER in 0.1 M potassium hydroxide (KOH) solution, comparable with those of state-of-the-art IrO 2 . The Zn–air battery based on a NiFe–W 18 O 49 cathode displays a long-term cycling durability of over 180 h, superior to the battery with a commercial Pt/C–IrO 2 cathode. Combined experimental analysis and density functional theory calculations unveil that the distorted geometric structure and regulated electronic structure of W 18 O 49 contribute crucially to the activation of its inert catalytic activity.