Enhanced photocatalytic degradation of chlorinated pesticides and polychlorinated biphenyls using Mo–TiO2/GO/MS nanocomposite

Mill scale (MS), which refers to iron waste, was used to synthesize Mo–TiO2/GO/MS nanocomposite for the photodegradation of persistent organic pollutants (POPs) via UV irradiation. By combining Mo–TiO2 as a semiconductor, graphene oxide as a supporter, and mill scale as magnetic material, we conceptually synthesized smart nanocomposite with visible light absorption and magnetic properties toward photocatalytic oxidation of POPs. Several analysis techniques such as TEM, XRD, XPS, and UV–vis were used to characterize the synthesized nanocomposite which exhibited a crystal size of 10 ± 2 nm, and optical absorption enhancement with calculated bandgap energy of 2.75eV. The photocatalytic degradation performance of 17 chlorinated pesticides was selected for testing through the synthesized nanocomposite. The photocatalytic performance using Mo–TiO2/GO/MS nanocomposite was more than 55%. The highest photocatalyst efficiency of 94.29% was achieved for the typical pesticide Endrine from water under UV illumination in less than 60 min. Additionally, polychlorinated biphenyls such as PCB 148 and PCB 15 have been effectively photocatalytic degraded with a removal efficiency of 83.42% and 67.82%, respectively. All degradation reactions of the tested persistent organic pollutants are pseudo-first-order. The enhanced photocatalytic activity was achieved by the Mo–TiO2/GO/MS catalyst relating to its good adsorption activity and efficient electron-hole charge separation.