The role of Preparation Technique on the Structure, Electrical Properties of CoxZn1-xFe2O4 and its Electrocatalytic Effect on Hydrogen Evolution Reaction

Abstract

Zinc-ferrite ZnFe 2 O 4 and Co x Zn 1-x Fe 2 O 4 (x= 0.2, 0.5 and 0.8) were prepared by two different techniques. The first was the solid state reaction based on utilizing electric arc furnace dust (waste material), and the second was the microwave treatment (pure materials). The structure and characterization of the prepared samples were studied by using XRD and SEM which ensured the formation of cubic spinel structure with some hematite phases. The physical properties as the density and porosity were measured where the microwave samples showed lower porosity and higher density than the solid state samples. Semiconducting properties has been observed for the prepared samples. The electrocatalytic activity of the hydrogen evolution reaction (HER) has been studied for all the samples in 1.0 M KOH (25 °C) by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance techniques. The results showed that the catalytic activity increased with increase of Co content as the surface area and the total pore volume increases in the ferrite prepared by solid state method while Co 0.2 Zn 0.8 Fe 2 O 4 prepared by microwave method showed the highest surface area and optimum improvement in the apparent HER catalytic activity. Lower resistance and faster charge transfer were shown for Co x Zn 1-x Fe 2 O 4 than the pure phase.