Study of photo catalytical, antimicrobial activity, dielectric and ac impedance properties of Zn doped Mg nanoferrites synthesized from citrate gel auto combustion method

Mg-Zn nano ferrites with composition Mg(1-x)ZnxFe2O4 where x = 0.0 to 1.0 with 0.2 variation, were fabricated through citrate gel auto combustion method with step wise variation 0.2 mol%. UV-Visible spectroscopy confirmed the direct allowed transitions and optical band gap increased from 2.61ev to 2.71 with the addition of dopant Zn. The PL spectroscopy revealed that the broad near band edge emission in visible range 350-450 nm wavelength region. Antibacterial efficiency of the nano ferrites enhanced with the antibacterial dopant element Zn against gram positive Bacillus subtilis (MTCC 121) and gram negative Escherichia coli (MTCC 1687) strains. Organic dyes such as methylene blue and acid red were used to do photocatalytical degradation process and significant rate of degradation was found. Frequency dependent AC conductivity (sigma(ac)) of the nano ferrites increased as a function of temperature and dopant Zn content. Dielectric parameters such as dielectric constant, dielectric loss (tan delta) were decreased with applied frequency. The results of dielectric studies reveals that the dielectric dispersion because of the hopping mechanism of electrons takes place in between Fe2+ and Fe3+ ions.