A fibrous Ir-doped NiFeOx on two-dimensional materials for high efficiency oxygen evolution reaction (OER)

As a clean and renewable energy, hydrogen gas can be generated from water electrolysis which also involves the sluggish oxygen evolution reaction (OER). The main commercial catalysts for OER are Ir and Ru based but have the problems of high cost and poor cycling stability. Herein, we designed a new electrocatalyst based on Ni, Fe and Ir compounds loaded on a unique two-dimensional carbon material, which can efficiently catalyze OER with high stability in alkaline solution. The composite was prepared by physical vapor deposition, showing a fibrous microscopic morphology with uniform particle size distribution. The fibrous structure ensured the exposure of active sites, which further improved OER activity. The loading of metallic iridium in the material is only 0.0858 mg cm−2. The catalytic activity of OER was maintained for 54 h under alkaline conditions at a current density of 50 mA cm−2 without significant changes in current density. Characterization showed that the excellent activity and stability of the catalysts originated from the Ir insertion into the NiFe2O4 lattice.