Visible‐Light‐Active Magnetic CuFe 2 O 4 and Fe 3 O 4 Nanoparticles: Efficient Photocatalysts for Allura Red Dye Degradation With Enhanced Antibacterial Activity

ABSTRACT In this study, magnetic copper ferrite (CuFe 2 O 4 ) and magnetite (Fe 3 O 4 ) nanoparticles (NPs) were successfully synthesized. The as‐synthesized NPs were evaluated as photocatalysts for the degradation of allura red (AR) dye under visible light irradiation. X‐ray diffraction (XRD), Fourier transform infrared spectra (FTIR), energy dispersive x‐ray (EDX), scanning electron microscopy (SEM), UV–vis diffuse reflectance (UV–vis DRS), and photoluminescence (PL) analysis were used for to reveal the structural and optoelectronic properties of synthesized materials. The bandgap energies of CuFe 2 O 4 and Fe 3 O 4 NPs were found to be 1.41 and 1.51 eV, respectively, indicating their suitability for visible light photocatalysis. Under optimized reaction conditions (AR concentration = 20 mg/L, photocatalyst dosage = 0.25 g/L, pH = 5, irradiation time = 180 min), CuFe 2 O 4 and Fe 3 O 4 achieved 94.84 and 81.79% AR dye degradation, respectively. The enhanced photocatalytic activity of CuFe 2 O 4 NPs was attributed to its superior light absorption capacity and efficient electron–hole pair (e − /h + ) separation. Moreover, CuFe 2 O 4 demonstrated higher antibacterial activity against Escherichia coli (E.coli) , whereas Fe 3 O 4 exhibited higher activity against Staphylococcus aureus . Against E. coli , the maximum inhibition zones of 9.00 ± 0.58 mm and 5.62 ± 0.48 mm were observed for CuFe 2 O 4 and Fe 3 O 4 NPs, respectively, at 500 µg/mL photocatalyst dosage. These findings highlight the potential of CuFe 2 O 4 as an efficient multifunctional material for wastewater treatment and antimicrobial applications, offering a sustainable approach for environmental remediation.