Camphoric Acid in Nanomagnetic Photocatalyst Synthesis: Direct and Indirect Visible Light Photocatalytic Degradation of PCBs

In this study, camphoric acid was used as a carbon source in the synthesis of the catalyst for the first time. The new Fe₃O₄/C/SiO₂/TiO₂ and Fe₃O₄/C/TiO₂ magnetic nano-semiconductors were synthesized and used for hydrogen peroxide-free photodegradation of polychlorinated biphenyls (PCBs) in transformer oil (Askarel) and significant PCB 138 in aqueous solutions under visible light irradiation. Also, interestingly, direct degradation was carried out for Askarel oil in addition to the extraction-degradation method. These nano-reduced band gap semiconductors (2.10 eV) were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N₂ adsorption-desorption isotherm analyses, and vibrating sample magnetometer (VSM). The high photocatalytic performance compared to Fe₃O₄/C/TiO₂ and P25 in direct and indirect (extraction-degradation) degradation besides its convenient magnetic recovery are the main advantages of Fe₃O₄/C/SiO₂/TiO₂.