Magnetically separable Nd and Mn co-doped SrFe12O19 hexa-ferrites nanostructures for the evaluation of structural, magnetic and photo-catalytic studies under solar irradiation for the crystal violet dye removal from the industrial wastes

In the current research study, Nd & Mn co-doped strontium hexa-ferrite Sr1-xNdxFe12-yMnyO19 nanoparticles (NPs) were fabricated using facile micro-emulsion approach. The as-fabricated bare and co-doped materials were characterized for the structural X-ray diffraction (XRD), Raman and Fourier Transform of Infrared (FTIR), magnetic and photo-catalytic activities (PCA). The structural characterization confirms the synthesis of single phase M-type Sr-hexa-ferrite, along with successful doping of Nd and Mn ions at tetrahedral/octahedral site. The crystallite/grain size was observed to increase from 18 to 27 nm. The vibrating sample magnetometer (VSM) analysis revealed that the saturation magnetization (Ms), coersivity (Hc) and remanence increases on co-doping. Optical and band gap studies revealed the narrowing of energy band-gap (Eg) which decreases from (2.18 eV-1.98 eV) on Nd and Mn doping which might be attributed to the new energy level generation in the co-doped materials. BET surface analysis shows well porous nature of the Nd and Mn co-doped materials with pore size 74 m2/g in comparison to 56 m2/g of un-doped material. The PCA was determined by solar-light degradation of crystal violet (CV) dye as industrial model contaminant. The results revealed that Nd and Mn co-doped Sr1-xNdxFe12-yMnyO19 NPs efficiently degraded CV dye (90.7%) when compared with (36.8%) of un-doped SrFe12O19 NPs in the 90 min of solar-light exposure. This increase in the PCA was ascribed because of the narrow band gap and defected structure of Nd and Mn co-doped Sr1-xNdxFe12-yMnyO19 NPs. The stability and reusability tests revealed the excellent stability of the photo-catalyst which is only 1.10% loss observed after 5 repeated rounds which indicate its potential stability and reuse. The results of the application studies of Nd and Mn co-doped Sr1-xNdxFe12-yMnyO19 NPs revealed the potential uses for various electrical, as magnetic materials and for the remediation of toxic contaminants from the various industrial units and environment.

Automated summary

In this study, Nd & Mn co-doped strontium hexa-ferrite Sr1-xNdxFe12-yMnyO19 nanoparticles were synthesized using a simple micro-emulsion method. The co-doped materials exhibited improved structural, magnetic, and photo-catalytic properties compared to the bare material. The narrow band gap and defect structure of the co-doped nanoparticles contributed to their enhanced photo-catalytic activity. The results demonstrate the potential applications of these co-doped nanoparticles in various electrical and magnetic materials, as well as in the remediation of toxic contaminants.