Nanostructured Zn0.1Co2.9O4 material: Synthesis, characterization and its applications for energy storage and electrocatalytic dye degradation

Abstract

This article presents the synthesis and characterization of a cobalt oxide nanomaterial with potential applications in dye degradation and energy storage. The nanomaterial, Zn-doped cobalt oxide (Zn0.1Co2.9O4), was synthesized using a coprecipitation method followed by calcination at 300 °C for 5 h. Various techniques including XRD, TEM, and BET were employed to analyze the phase formation, particle size, morphology, and surface area of the calcined sample. The XRD analysis confirmed the phase purity of the material, revealing a nanocrystalline structure with an average crystallite size of 10 nm. TEM imaging revealed spherical-shaped particles with a mean particle size of 11 nm. The material exhibited mesoporous characteristics, with a surface area of 60 m2/g and a pore size of 33 nm according to BET analysis. Cyclic voltammetry (CV) measurements conducted at different scan rates demonstrated the redox behavior of the material, as evidenced by the presence of oxidation and reduction peaks. Galvanostatic charge–discharge (GCD) experiments revealed a specific capacitance (Cs) of 117 F/g at a current density of 0.1 A/g, which decreased to 78 F/g at 1 A/g. The electrocatalytic dye degradation of methyl orange dye (5 ppm) was carried out using a stainless steel electrode coated with the Zn0.1Co2.9O4 nanomaterial. An applied potential of 15 V and a current of 0.03 A resulted in a 98% degradation of the dye after 30 min. The experiment was repeated for five successive cycles, yielding consistent levels of dye degradation.