1D hollow MFe₂O₄ (M = Cu, Co, Ni) fibers by Solution Blow Spinning for oxygen evolution reaction

The development of low-cost transition metal electrocatalysts for the oxygen evolution reaction (OER) has been the focus of intense research. Herein, we report for the first time the synthesis of one dimensional (1D) hollow MFe₂O₄ (M = Cu, Co and Ni) fibers by the Solution Blow Spinning (SBS) technique and their performance towards OER in alkaline medium. The formation mechanism of the hollow structure and the influence of the fibrillar morphology on the performance of electrocatalysts were discussed. Electrocatalytic performance to generate 10 mA cm^-2 with low overpotential followed the sequence: CuFe₂O₄ > CoFe₂O₄ > NiFe₂O₄. The improved OER performance of hollow CuFe₂O₄ fibers is due to a superior number of active sites exposed to surface reactions, confirmed by a remarkable electrochemically active surface area (ECSA) of 225 cm². Solution blow spun hollow ferrite fibers showed better electrocatalytic activity towards OER than 1D, 2D and 3D ferrite-based nanostructures reported in the literature.