Tailored dielectric, optical properties and photocatalytic performance of Mg–Zn nanoferrites by Cu2+ substitution

Abstract

This research article is focused on the scrutinization of dielectric, optical and photocatalytic activity of Mg0.8Zn0.2−xCuxFe2O4 (MZC) nanoferrites upon the substitution of Cu2+ ions range (0 ≤ x ≤ 0.2; step 0.04). The dielectric constant and conductivity of MZC nanoferrite manifested the higher values than the pristine one. This leveraging demeanor is originated from the effective role of Fe2+ and Fe3+ in octahedral sites; as a result of occupying Cu ions in tetrahedral sites only. All MZC nanoferrites have the two types of losses; conduction and relaxation losses. The conduction process of MZC nanoferrites is attributed to three different species through different temperature ranges. Nyquist plot manifested that grain and grain boundary resistances were decreased and relaxation time enhanced from 0.79 to 7.95 µs with Cu substitution. Tauc's plots introduced direct allowed Eg for MZC nanoparticles with a red shift from (2.16 eV at x = 0.0 to 1.67 eV at x = 0.2). The degradation efficiency of RhB over MZC photocatalyst is enhanced comparing with that of pristine RhB; 92.39% for x = 0.2 in 300 min. The nanoferrite Mg0.8Cu0.2Fe2O4 (x = 0.2) has the optimal merits; highest dielectric constant, conductivity, photodegradation percentage, besides lowest energy gap and moderate loss make it advisable for sundry applications as an excellent photocatalyst for wastewater treatment besides high-frequency applications and transformers cores.