ZnFe2O4 nanofibers decorated with NiCo2O4 nanosheets as an efficient electrocatalyst for the oxygen evolution reaction

Abstract

A NiCo₂O₄/ZnFe₂O₄ (NCO/ZFO) nanocomposite with a hierarchical structure has been successfully prepared by combining the electrospinning and solvothermal methods. The uniform growth of NiCo₂O₄ nanosheets (NCO NSs) on the surface of ZnFe₂O₄ nanofibers (ZFO NFs) not only provides a large specific surface area for high exposure of active sites, but also enhances the structural stability of the NCO/ZFO nanocomposite. Moreover, the synergistic effect between the NCO NSs and ZFO NFs improves the conductivity as well as the electron transfer, thereby enhancing the electroactivity and stability of the NCO/ZFO nanocomposite for the oxygen evolution reaction (OER). The NCO/ZFO nanocomposite shows a low overpotential of 340 mV (with iR correction) at 10 mA cm⁻² and a residual current density of 81% after 50 h of continuous reaction. This work provides a simple route for developing a low-cost and stable electrocatalyst with high efficiency for the OER.