Robustic and hybrid cobalt doped BaFe12O19 hexaferrites for the photocatalytic degradation of Congo Red for wastewater treatment

The industrial sector faces a significant challenge in finding the highly effective and efficient treatments for harmful dye-based color effluents. In this study, pure and cobalt doped barium hexaferrite of chemical formula, Ba_1-xCo_xFe₁₂O₁₉ (x = 0-0.06) are made via sol-gel auto-combustion (SC) methodology. These nano hexaferrite based catalysts are employed for the photodegradation of Congo Red (CR) pollutant. X-rays diffraction investigation confirms the creation of pristine M-type with a hexagonal structure for the prepared hexaferrites. Field emission scanning electron microscopy analysis shows the existence of the hexagonal-shaped grains with well-defined grain boundaries. The reduction in the band gap of prepared hexaferrites are observed with the cobalt doping which is helpful in enhancing the photocatalytic performance. The X-ray photoelectron spectroscopy examination verifies the oxidation states of all elements found in the fabricated specimens. From the photocatalytic measurements, it is observed that the CR dye attains the removal percentage of 87.90%, 90.73%, 91.86% and 94.88% for the BaFe₁₂O₁₉ (x = 0.00), Ba_0.08Co_0.02Fe₁₂O₁₉ (x = 0.02), Ba_0.06Co_0.04Fe₁₂O₁₉ (x = 0.04), and Ba_0.04Co_0.06Fe₁₂O₁₉ (x = 0.06) hexaferrites under the natural sunlight of two hours. In addition, the reusability potential of prepared hexaferrites is also studied over the six consecutive experimental cycles. The excellent photodegradation performance of the Co- doped barium M-type hexaferrites for the removal of CR dye makes them highly useful for the wastewater remediation.