Photocatalytic degradation of organic dyes on magnetically separable barium hexaferrite as photocatalyst under conditions of visible light irradiation.

In this paper, we present the first attempt to evaluate the role of carboxymethyl cellulose (CMC) as a chelating agent in the sol–gel auto-combustion method of producing barium hexaferrite (BaFe₁₂O₁₉). We also report the application of the system as a photocatalyst for dye degradation. The formation, morphology, and crystalline structure of the synthesized nanoparticles are determined using XRD, SEM, EDS, VSM, FTIR, and TEM techniques. High efficiency under visible light, with a band gap of 1.62 eV and a BET surface of 17.93 m²/g, has been observed for the BaFe₁₂O₁₉ catalyst. The operating parameters, such as reaction time, initial dye concentration, light intensity, reusability, and dye type, are studied. Degradation rates as high as 98.26% (K_app = 0.082 min^–1) and 89.07% (K_app = 0.0743 min^–1) were obtained for cases of methylene blue and malachite green under conditions of visible light irradiations when BaFe₁₂O₁₉ was used. The BaFe₁₂O₁₉ catalyst has been shown to exhibit a high degradation performance for cationic dyes. Furthermore, BaFe₁₂O₁₉ magnetic nanoparticles show excellent reusability for dye degradation because the photocatalyst did not exhibit a significant decrease in its activity even after five runs (81.56%). As a result, the current study confirmed that photocatalytic degradation was a promising technology for saving water and treating wastewater formed from textile dye industries. The technique can be used to study the efficiency of photocatalytic degradation and understand the process of recycling waste effluents under conditions of minimized water use. [ABSTRACT FROM AUTHOR]