Preparation, magnetic and photocatalytic properties of nano-structured SrFe12O19 obtained via an optimized mechano-thermal route using celestite ore

Nano-structured SrFe12O19 was synthesized from celestite ore, using two routes of the mechano-thermal method. Ball-milling was employed, and the thermal analysis data confirmed the mechanical activation. After calcination at 1000 degrees C, the results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicated the formation of single-phase strontium hexaferrite with a mean particle size of 196 nm and plate-like hexagonal structure. The vibrating sample magnetometer (VSM) study exhibited the coercivity and saturation magnetization values of 4800 Oe and 63 emu/g, respectively. The diffusion reflectance spectroscopy (DRS) test displayed light absorption in the range of visible light with a band-gap energy value of 1.78 eV. As a photocatalyst, a degradation efficiency of 84% was obtained for an initial methylene blue concentration of 5 mg/L with a photocatalyst dosage of 4 g/L after 180 min of visible light irradiation. Also, the degradation mechanism and kinetics were described in detail. A study on the reusability and stability indicated good recyclability of the prepared powder during the cyclical degradation.

Automated summary

The study synthesized nano-structured SrFe12O19 from celestite ore using mechano-thermal methods. The material exhibited high degradation efficiency and stability under visible light, indicating potential as a photocatalyst.