Photocatalytic Degradation of Congo Red Dye from Aqueous Environment Using Cobalt Ferrite Nanostructures: Development, Characterization, and Photocatalytic Performance

Abstract

Highly efficient and effective treatments of hazardous dye-based color effluents are a major problem in the industrial sector. In this research, the cobalt ferrite (CoFe2O4) catalyst was produced and used for the degradation of Congo red (CR) as a model dye from aqueous solution. For a said purpose, cobalt ferrite (CoFe2O4) nanostructures with photocatalytic degradation potential were engineered via co-precipitation method using Fe2(SO4)3, CoO2, and triethylene glycol (as a stabilizing agent). As prepared, CoFe2O4 nanostructures were further surface-functionalized with 3-APTES and tested for CR degradation. The prepared CoFe2O4 nanostructures were characterized by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), and Brunauer-Emmitt-Teller (BET) analysis. UV-visible absorption was used to measure the optical band gap of prepared CoFe2O4 nanostructures through Tauc plots. The as-prepared CoFe2O4 nanostructure bandgap was found to be 2.71 EV while using an acidic medium. The degradation rates of CR dye for bs-CoFe2O4, as-CoFe2O4, and fs-CoFe2O4 nanostructures at pH 9 were 84, 87, and 92%, respectively. Furthermore, the influences of various process parameters, i.e., the effect of catalyst dose, contact time, dye dose/concentration, pH effect, and effect of different acids, were checked for the prepared three types of nanostructures, i.e., bs-CoFe2O4, as-CoFe2O4, and fs-CoFe2O4. The kinetics models properly explained that the reaction of degradation following pseudo-first-order kinetics.