Band gap tuning of BaFe12O19 with Mg and Mn doping to enhance solar light absorption for photocatalytic application

Mg and Mn ions doping were performed in barium hexaferrite (Ba1-xMgxFe12-yMnyO19) (x = 0.0, 0.30, 0.45, 0.60, 0.75, 0.90) and (y = 0.0, 0.15, 0.30, 0.45, 0.60, 0.75) via facile micro-emulsion route. XRD analysis revealed the formation of single-phase hexagonal geometry of Ba1-xMgxFe12-yMnyO19 with the successful doping of the Mg and Mn ions. The average crystallite size was 19.5 nm, which was increased by increasing the dopant contents. The functional groups were identified by FTIR analysis. The dopant contents (Mg and Mn) affected the dielectric properties Ba1-xMgxFe12-yMnyO19 and AC conductivity was increased, while dielectric loss, tangent loss, and resistivity were decreased as the concentration of dopant ions was increased. The Tauc's plot was used for the band gap estimation of Ba1-xMgxFe12-yMnyO19, the band gap values were decreased from 2.94 to 1.90 (eV) due to generation Fermi energy and change in the Ba2+ ions at the tetra- and octahedral locations. Photocatalytic activity (PCA) was performed under visible light by degrading Rhodamine B (RhB) dye. The RhB dye was degraded up to 85% within 50 minutes following the first order reaction kinetics with 0.0224 min(-1) rate constant. The results revealed that the BaFe12O19 NPs the band gap can be tuned by doping the Mg and Mn ions to enhance the visible light harvesting for economical photocatalytic applications in various fields.

Automated summary

Mg and Mn ion doping in barium hexaferrite resulted in single-phase hexagonal geometry with changes in crystallite size and band gap values. The doping influenced the dielectric properties and increased AC conductivity while decreasing dielectric loss, tangent loss, and resistivity. The photocatalytic activity under visible light showed significant degradation of Rhodamine B dye, indicating potential for economical applications in various fields.