In this study, Cu0.5Zn0.5FeAlO4 and ZnAlCrO4 nanoparticles were successfully synthesized via eco-friendly methods and thoroughly characterized using XRD, BET, FESEM, TEM, EDX, Mapping, UV-Vis DRS, and VSM techniques. XRD confirmed the formation of pure cubic spinel structures with high crystallinity, with average crystallite sizes of 12 nm and 11 nm for Cu0.5Zn0.5FeAlO4 and ZnAlCrO4, respectively. FESEM and TEM revealed spherical and irregular morphology (25–30 nm) for Cu0.5Zn0.5FeAlO4 and uniform spherical morphology (~30 nm) for ZnAlCrO4 nanoparticles. EDX and Mapping analyses confirmed the uniform composition and distribution of elements in the Cu0.5Zn0.5FeAlO4 and ZnAlCrO4 structures and demonstrated the purity and structural integrity of the synthesized nanoparticles. BET analysis revealed specific surface areas of 46.348 m²/g and 46.106 m²/g for Cu0.5Zn0.5FeAlO4 and ZnAlCrO4, respectively. UV-Vis DRS spectra showed band gaps of 1.95 and 2.01 eV for Cu0.5Zn0.5FeAlO4 and ZnAlCrO4 nanoparticles, respectively, indicating their potential for photocatalysis under visible light. VSM analysis showed that Cu0.5Zn0.5FeAlO4 nanoparticles exhibited superparamagnetic behavior with a saturation magnetization of 3.74 emu/g, allowing for easy magnetic separation and reusability. Cu0.5Zn0.5FeAlO4 Magnetic nanoparticles were investigated for the photocatalytic degradation of Reactive Blue 222 dye. The results indicated that 95% of the RB 222 dye and 63% of the total organic carbon (TOC) were removed within 45 min. Also, ZnAlCrO4 nanoparticles were studied for the photocatalytic degradation of Reactive Yellow 145 dye. The results indicated that 91% of the RY145 dye and 52% of the total organic carbon (TOC) were removed within 30 min. Radical scavenger experiments suggested that hydroxyl radicals (•OH) were the dominant reactive species in both cases. Reusability tests demonstrated excellent stability of Cu0.5Zn0.5FeAlO4 and ZnAlCrO4 nanoparticles with minimal loss of activity.
