Abstract
To design highly efficient and low-cost electrocatalysts for oxygen evolution reaction (OER) is a great challenge for electrochemical water splitting. Herein, we report the preparation of hierarchical Fe-doped NiOx nanotubes assembled from ultrathin nanosheets with a thickness of 2.4nm. X-ray photoelectron spectroscopy (XPS) spectra, X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy investigations have been suggested that the incorporation of Fe results in abundant trivalent nickel and nickel vacancies. Benefitting from their unique geometric and electronic structure, the as-prepared hierarchical Fe-doped NiOx nanotubes exhibit outstanding OER activity and stability, with overpotential of 310mV and a small Tafel slope of ~ 49mVdec−1 at 10mAcm−2.
The hierarchical Fe-doped NiOx nanotubes assembled from 10-at.-layer ultrathin nanosheets containing trivalent nickel has been prepared. The as-prepared hierarchical Fe-doped NiOx nanotubes exhibit remarkable catalytic activity for the oxygen evolution reaction (OER) in alkaline electrolytes. [Display omitted]
•For the first time, we have discovered that trivalent nickel was formed in Fe-doped Ni oxide nanostructure.•The hierarchical Fe-doped NiOx nanotubes are assembled from 10-at.-layer ultrathin nanosheets.•The hierarchical Fe-doped NiOx nanotubes is among the most active OER catalysts and their OER activity was much higher than that of IrO2.