Zn and Mn doped Ba1-xZnxFe12-yMnyO19 as highly photoactive under visible light with enhanced electrochemical and dielectric properties

Abstract

The zinc and manganese substituted barium hexaferrite (Ba1-xZnxFe12-yMnyO19) nanoparticles (0.00 < x < 0.90; 0.00 < y < 0.75) was fabricated by microemulsion approach and effect of substitution was evaluated on the basis of electrochemical, dielectric and photocatalytic properties. The Ba1-xZnxFe12-yMnyO19 NPs exhibited ferrite structure with hexagonal phase having P63/mmc space group and the crystallite size was in 16–21 nm range. The microstructure of Ba1-xZnxFe12-yMnyO19 NPs showed the agglomerated spherical structure. The effect of doping on the electrochemical property of the fabricated material was investigated via cyclic voltammetry. The energy band gap was estimated from UV–visible absorbance spectra using Tauc plots, band gap values show a decreasing trend by increasing the dopant contents, i.e., 1.89 (eV) to 1.31 (eV) for doped samples. The low band gap value material has promising potential in optical and catalytic applications. Dielectric constant and dielectric loss of Ba1-xZnxFe12-yMnyO19 NPs were monitored in 20 Hz to 0.017 GHz range. By increasing the dopants content, tangent loss and dielectric loss were increased, while the AC conductivity was decreased. Moreover, photocatalytic efficiency was investigated by degrading methyl green (MG) dye under visible light irradiation and it was found that the substituted NPs exhibited maximum degradation of 85.1% of MG dye following the first order kinetic with rate constant of 0.0188 min−1. The results depict that the properties of BaFe12O19 can be tuned by Zn and Mn doping for potential application in photocatalysis.