Functionally Graded Chitosan Ferrite Beads for Photocatalytic Degradation of Eriochrome Black T and Congo Red Dyes

Abstract Heterogeneous photocatalysis plays a vital character in the degradation of organic dyes and their by-products, which pose a threat to aquatic and terrestrial life if discharged in wastewater. Herein, we developed a one-pot synthesis method for producing cobalt-ferrite (CoFe2O4) and nickel-ferrite (NiFe2O4) nanoparticles via a co-precipitation technique. Then prepared five different nanocomposite beads, including chitosan beads, Chi-CoFe2O4-1, Chi-CoFe2O4-2, Chi-NiFe2O4-1, and Chi-NiFe2O4-2 in an aqueous acidic system. All the nanocomposite beads were structurally characterized by Scanning Electron Microscope, X-ray Diffraction, and Fourier Transform Infrared Spectroscopy analysis. Further, the as-prepared nanocomposite beads were utilized in the photo-degradation of Eriochrome black T, (EBT) and Congo red (CR) organic dyes. The outcomes demonstrated that, after 110 min of visible light illumination, the maximum photo-degradation of EBT dye reached 93%. While the maximum photo-degradation of CR dye reached 92% within 90 min by Chi-NiFe2O4-2. The corresponding turnover frequencies were 1257.5 kg− 1/sec, 1287 kg− 1/sec, 1318.18 kg− 1/sec, 1363 kg− 1 /sec, and 1393 kg− 1/sec, respectively. Furthermore, the turnover numbers were 2.26x10^7 Kg− 1/sec, 2.3×10×7 kg− 1/sec, 2.37×10×7 kg− 1/sec, 2.45×10×7 kg− 1/sec, and 2.5x10×7 kg− 1/sec for Chitosan beads, Chi/CoFe2O4 − 1, Chi/CoFe2O4 − 2, Chi/NiFe2O4 − 1, and Chi/NiFe2O4 − 2 respectively. Based on the findings, it can be concluded that engineered nanocomposite beads have a significant potential for visible-light-driven catalytic remediation of hazardous dyes. These results also suggest that there is a need for further research on the photocatalytic abatement of organic contaminants.