AC conductivity, complex impedance and photocatalytic applications of Co2+ substituted Mg-Zn nanoferrite

This paper is focused on the investigation of dielectric parameters, optical properties, and photocatalytic activity of Mg0.8Zn0.2-xCoxFe2O4 (MZCFO) nanoferrites upon the substitution of Co2+ ions range (0 <= x <= 0.2; step 0.04). The dielectric constant, dielectric loss, and ac conductivity variations, with frequency for all MZCFO samples, can be interpreted based on Maxwell-Wagner interfacial polarization. The lowest value of dielectric loss (similar to 0.45) was recorded for the ferrite sample, with x=0.08 at room temperature and a frequency of 5 MHz. The dielectric constant, dielectric loss, and ac conductivity were found to adopt a climbing trend with raising the temperature. The impedance formalism showed a decrease in the grain boundaries resistance (R-gb) with increasing Co2+ content and was calculated by implementing the Cole-Cole plot. The UV-Vis spectrum, along with Tauc's equation, was used to estimate the bandgap of MZCFO ferrite nanoparticles, which was found to tune successfully with the addition of Co2+ ions from 1.96 to 1.81 eV. This finding gives escalation to the enhancement of photocatalytic activity, and degradation efficiency of MB dyes under the illumination of visible-light experiences an increase from 65 to 95% with increasing the addition of the nanoferrite with (x=0.2). The optimum properties of the nanoferrite Mg0.8Co0.2Fe2O4, such as the high dielectric constant along with high conductivity, besides its ability for MB degradation, and so a peak success in water-treatment applications is predicted.