Facile synthesis of nanoparticle-stacked tungsten-doped nickel iron layered double hydroxide nanosheets for boosting oxygen evolution reaction

Developing highly efficient and cost-effective water oxidation catalysts to enhance the oxygen evolution reaction (OER) remains a significant challenge for electrochemical water splitting. Here, ultrathin tungsten-doped nickel iron layered double hydroxide (Ni-Fe-W LDH) nanosheets, which are composed of nanoparticles with size of 2 to 6 nanometers, have been directly grown on nickel foam (NF) using a facile and scalable water bath reaction. When applied as a catalyst for OER catalysis, this self-supported Ni-Fe-W LDH/NF shows superb OER activity, requiring low overpotentials of only 247 and 320 mV to attain current densities of 100 and 1000 mA cm(-2), respectively, with a small Tafel slope of 55 mV dec(-1) in 1.0 M KOH electrolyte. The high catalytic activity is attributed to the unique open porous structure, high density of crystalline-amorphous phase boundaries, abundant active sites, and enhanced conductivity resulting from the combination of W doping and Ni-Fe LDH. This work presents a general approach toward the large-scale fabrication of inexpensive trimetallic LDH-based OER electrocatalysts.