Investigating Dielectric, Magnetic, and Photocatalytic Properties of Copper Mixed Manganese Ferrite: Degradation of Methylene Blue

ABSTRACT

Magnetic materials, manganese ferrites (MnFe ₂ O ₄ ; MnF), and copper manganese ferrite (CuMnFe ₂ O ₄ ; CuMnF) were synthesized and characterized by different instrumental techniques in order to investigate various physicochemical properties. The XRD data disclosed single‐phase cubic spinel structure of CuMnF with an average crystallite size of 43 nm, whereas the crystallite size of MnF was 72.5 nm. Insertion of copper in the lattice of MnF altered its magnetic, dielectric, and catalytic properties. MnF and CuMnF showed superparamagnetic behavior where a decrease in the magnetization of MnF was observed with mixing of Cu as the temperature crossed the blocking temperature. Total density of states (TDOS) and band structure were calculated through density functional theory (DFT). Narrow bandgap ( E _g ) of CuMnF make it a potential candidate for photocatalytic applications. The photocatalytic activity of CuMnF was unveiled via degradation of methylene blue (MB). The optimized reaction conditions for efficient photocatalytic degradation of MB were time; 90 min, dose; 225 mg/L, dye conc; 9 ppm, temp; 45°C, and pH; 8 under UV flux; 1.67 × 10 ¹⁷ photons/sec. Photodegradation of MB over CuMnF followed first order kinetic model ( k = 0.016 min ⁻¹ ). TOC analysis revealed complete mineralization of the dye. Excellent recycling capability shows the potential of catalyst for large‐scale applications.