摘要

The development of highly efficient and inexpensive catalysts for oxygen evolving reactions (OERs) is extremely urgent for promoting the overall efficiency of water splitting. Herein we report the fabrication of a series of amorphous NiFeB nanoparticles with varying atomic ratios of Fe to (Ni + Fe) (chi(Fe)) by a facile chemical-reduction method. The amorphous NiFeB (chi(Fe) = 0.20) nanoparticles, combining the merits of in situ formation of borate-enriched NiFeOOH catalytic surface layers, intrinsic amorphous nanostructures, and an optimized degree of Fe doping, displayed highly active electrocatalytic performance towards the OER in a broad range of pH values (from alkaline to neutral conditions). The catalyst exhibited a relatively low overpotential of 216 mV with a Tafel slope of 40 mV/dec on Ni foam and 251 mV with a Tafel slope of 43 mV/dec on glassy carbon at 10 mA/cm(2) in a 1 M KOH solution, demonstrating much greater OER efficiency than that of commercial RuO2. Long-term stability testing of the OER performance of NiFeB (chi(Fe) = 0.20) by chronoamperometry (overpotential (eta) = 320 mV) over 200 h revealed no evidence of degradation. Facile, scalable synthesis and highly active water oxidation make the NiFeB nanoparticles very attractive for OER electrocatalysis.