Yttrium doped magnesium ferrite nanoparticles: a potential solar light driven photocatalyst for deterioration of hazardous dyes

Spinel ferrites have been gaining stupendous interest in science and technology due to their multifunctional properties. Herein, we have reported the synthesis of yttrium-doped magnesium ferrite, MgFe_2−xY_xO₄ (x = 0.00, 0.04 and 0.08), via the sol–gel auto-combustion method. X-ray diffraction (XRD) patterns confirm that the synthesized ferrites have crystallized in the cubic spinel phase. The Fourier transform infrared spectra (FTIR) reveal the characteristic vibrational bands corresponding to metal-oxygen stretching between 561 and 566 cm⁻¹ and 427–429 cm⁻¹. Y³⁺ doping demonstrates a drop in bandgap energy of MgFe₂O₄, extending their absorption into the visible region. The photoluminescence (PL) spectra disclose the efficient charge carrier separation of Y³⁺ -doped MgFe₂O₄. The field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM) images illustrate their aggregated morphology, while energy dispersive X-ray (EDX) analysis clarifies the successful insertion of Y³⁺ ions into the MgFe₂O₄ lattice. Brunauer–Emmett–Teller (BET) analysis reveals an escalation in porosity and textural characteristics. Vibrating sample magnetometry (VSM) indicates that Y³⁺ ion substitution reduces saturation magnetization and coercivity in pure MgFe₂O₄. The photocatalytic efficacy of MgFe_2−xY_xO₄ (x = 0.00, 0.04 and 0.08) was tested against methylene blue (MB) dye under direct sunlight. The results indicate that their efficiency magnifies with the rising Y³⁺ concentration and attains a maximum degrading capacity of 86% in a short period of 35 min. The Y³⁺-doped MgFe₂O₄ nanoferrites prove themselves as outstanding photocatalysts, exhibiting extraordinary properties like easy magnetic recovery, reusability and cost-effectiveness, serving as potential candidates for practical applications.