An oxycarbide-derived-carbon supported nickel ferrite/copper tungstate ternary composite for enhanced electrocatalytic activity towards the oxygen evolution reaction

Abstract

This work integrates a unique porous carbon with a binary heterostructured NiFe₂O₄/CuWO₄ composite to enhance electrocatalytic activity towards the oxygen evolution reaction. The NiFe₂O₄/CuWO₄ binary heterostructure was prepared through the conventional co-precipitation method. The porous carbon with turbostratic order was obtained by the selective etching of SiO₂ nanodomains from preceramic polymer-derived SiOC. Finally, an optimum ternary NiFe₂O₄/CuWO₄/C composite was prepared through hydrothermal treatment. Microstructural findings reveal that NiFe₂O₄/CuWO₄ nanocomposite particulates are distributed homogeneously within the porous carbon matrix. Electrochemical findings reveal that the optimum composite with uniform carbon distribution requires an overpotential of 360 mV to attain a current density of 10 mA cm⁻² with the lowest Tafel slope of 43 mV dec⁻¹ as opposed to 450 mV and 55 mV dec⁻¹, respectively, for the composites without carbon. The ternary composite demonstrated a stable potential over a prolonged period of 24 hours with enhanced mass activity. The improved electrocatalytic efficiency of the material is attributed to the presence of graphitic carbon and ample porosity within the additive carbon phase, which enhances the catalyst–electrolyte interaction interface area and electronic conductivity.