In-depth study of the photocatalytic performance of novel magnetic catalysts for efficient photocatalytic degradation of the dye orange G

Photocatalysts are often challenging to separate from solutions using conventional methods, presenting a significant hurdle to their practical utility. To tackle this issue, we have successfully developed a novel magnetic catalyst, Sr0.9M0.1Fe11.98Sm0.01Gd0.01O19, where (M=Ni, Zn, Mn, and Mg), via the auto-combustion sol-gel method. X-ray Diffraction (XRD) analysis confirmed a single-phase hexaferrite structure, with Rietveld refinement verifying the formation of a hexagonal lattice (space group P63/mmc) and crystallite sizes decreases with the doping elements. The formation of crystallographic sites in the hexaferrite structure was corroborated by Fourier Transform Infrared Spectroscopy (FTIR), while Raman spectroscopy indicated the presence of octahedral, tetrahedral, and trigonal-bipyramidal sites. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-Dispersive X-ray Spectroscopy (EDS) affirmed both the morphology and chemical composition homogeneity. UV-Vis NIR spectroscopy revealed energy band gaps, confirming the nanoparticles as semiconductors. X-ray Photoelectron Spectroscopy (XPS) analysis further validated the oxidation states of ions and the presence of oxygen vacancies. Magnetic measurements confirmed the ferrimagnetic behavior of the nanoparticles. In the context of photocatalytic applications, the nanoparticles demonstrated their efficacy by degrading dye Orange G (OG) under UV-Vis irradiation (300-800 nm), achieving an efficiency range of 69% to 83% after 105 minutes of exposure. These results are a novelty in the present work, revealing the stability and reproducibility of nanoparticles, making it possible to successfully meet the challenges associated with recycling in photocatalytic processes.