Ternary Metal Oxide–Chitosan Hybrids for Efficient Photocatalytic Remediation of Organic Pollutants from Wastewater

Abstract

Insufficient infrastructure for wastewater treatment stands as a critical global concern, profoundly impacting both the environment and public health. This issue is exacerbated by industrial effluents containing hazardous organic pollutants and dyes such as crystal violet (CV) and methyl orange (MO), posing significant environmental threats. This study introduces a novel approach utilizing chitosan microsphere-based iron–strontium–zinc oxide photocatalysts aimed at addressing the decontamination of these organic dyes. The synthesis of iron–strontium–zinc oxide was performed via co-precipitation method followed by its characterization using various techniques. The resulting CS-Fe₂SrZnO₄ microspheres exhibited a sleek morphology with an average diameter of 917 μm, featuring the confirmed presence of iron, strontium, and zinc oxide as ascertained by EDX analysis. With a bandgap of 1.24 eV, this material showcased remarkable efficacy in degrading CV and MO dyes under solar light irradiation. Optimized conditions were identified to attain maximum degradation efficiency for both dyes. The findings reveal that the maximum degradation achieved for MO and CV was 94% and 98%, respectively, at the optimized conditions (time; 60 min, catalyst dosage; 0.1 g, concentration 20 ppm, pH; 6 for MO and 8 for CV). The statistical analysis was also performed which supported the obtained results. The kinetics study showed that the degradation followed pseudo-first order kinetics with R² value of 0.96. The current study has a great environmental impact as the degradation of hazardous dyes reduces the health related risks. To our best knowledge, this is the first report on the combination of ternary metal oxides combined with chitosan for the degradation of hazardous dyes.