A facile method to synthesize boron-doped Ni/Fe alloy nano-chains as electrocatalyst for water oxidation

Abstract

Abstract We report a novel magnetic field assisted chemical reduction method for the synthesis of boron-doped Ni/Fe nano-chains as promising catalysts for the oxygen evolution reaction (OER). The boron-doped Ni/Fe nano-chains were synthesised in a one step process at room temperature using NaBH 4 as a reducing agent. The addition of boron reduced the magnetic moment of the intermediate synthesis products and produced nano-chains with a high specific surface area of 73.4 m 2 g −1 . The boron-doped Ni/Fe nano-chains exhibited catalytic performance superior to state-of-the-art Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3−δ perovskite and RuO 2 noble metal oxide catalysts. The mass normalized activity of the boron-doped Ni/Fe nano-chains measured at an overpotential of 0.35 V was 64.0 A g −1 , with a Tafel slope of only 40 mV dec −1 . The excellent performance of the boron-doped Ni/Fe nano-chains can be attributed to the uniform elemental distribution and highly amorphous structure of the B-doped nano-chains. These results provide new insights into the effect of doping transition-metal based OER catalysts with non-metallic elements. The study demonstrates a facile approach to prepare transition metal nano-chains using magnetic field assisted chemical reduction method as cheap and highly active catalysts for electrochemical water oxidation.