Fabrication of Trimetallic Fe-Co-Ni Electrocatalysts for Highly Efficient Oxygen Evolution Reaction.

The development of inexpensive and well-activated water-splitting catalysts is required to reduce the use of conventional fossil fuels. In this study, a trimetallic Fe-Co-Ni catalyst was fabricated using a simple ion electrodeposition method. The metal deposition was performed using cyclic voltammetry, which was more efficient than constant-voltage deposition and significantly increased the stability of the catalyst. The synthesized material presented the morphology of a nanoflower in which the nanosheets were agglomerated. The Fe-Co-Ni catalyst exhibited excellent oxygen evolution reaction (OER) properties because the charge-transfer rate was improved owing to the synergistic effect of the metals. The OER was performed in a 1 M KOH solution using a three-electrode system, and the overpotential was 302 mV at 100 mA/cm 2 . In addition, the Fe-Co-Ni catalyst exhibited excellent stability in alkaline solution for more than 48 h at 200 mA/cm 2 . The results show that the method for preparing Fe-Co-Ni significantly improves its catalytic activity, and the resulting material could be used as an economical and efficient catalyst in future.