In the present thesis, CoAlFeO4 magnetic nanoparticles were successfully synthesized through a green synthesis route and evaluated as a visiblelight driven photocatalyst for tetracycline degradation. Structural, morphological, elemental, optical, textural and magnetic properties of CoAlFeO4 nanoparticles were studied by various characterization techniques. The formation of cubic spinel structure of CoAlFeO4 was confirmed from XRD data and the average crystallite size was estimated to be 15 nm. FESEM and TEM observations revealed that the dimension of synthesized particles was in the nanoscale and nearly spherical in morphology with the average particle size in the range of 30-40 nm. EDX analysis confirmed the presence of Co, Al, Fe, and O elements in the sample. Elemental mapping studies exhibited a uniform distribution of all these elements in the nanoparticles. BET analysis of the as-synthesized catalyst gave a specific surface area of 36.24 m2 g⁻1 which would provide accessible active sites for photocatalytic reaction. The optical band gap energy of the nanoparticles was found to be 1.90 eV. Magnetic property investigation revealed that the nanoparticles exhibited ferromagnetic behavior with a saturation magnetization of 6.32 emu g⁻1 which would be helpful for magnetic separation of the photocatalyst. The photocatalytic activity was determined using tetracycline as a model organic pollutant under visible-light irradiation. The as-synthesized CoAlFeO4 magnetic nanoparticles could achieve 91% of tetracycline degradation in 60 min. In addition, the catalyst displayed good photocatalytic activity after four consecutive reuses with only a slight decrease in the photocatalytic efficiency which confirmed its acceptable stability and reusability.
