Photocatalytic Removal of the Endocrine Disruptor Chlorpyrifos using a ZnO.MoO3 Composite Supported on Al2O3

Chlorpyrifos is an endocrine disruptor pesticide that induces breast cancer cell proliferation through Estrogen receptor alpha pathway in humans. It also has toxic effects on some beneficial insects like bees, wasps, and arthropods, even low levels of CP can kill fish in water. Thus, it is important to efficiently remove this compound from wastewaters to get rid of its hazardous effects. Al2O3 supported ZnO.MoO3 composite was prepared as an efficient material for photo-degradation of chlorpyrifos under UV irradiation and characterized by SEM-EDX, XRD and TG techniques. The XRD analysis showed the orthorhombic structures with band gap of 2.86 eV for ZnO.MoO3/Al2O3 which was 2.96 eV for MoO3/Al2O3. The kinetics of degradation depicted that ZnO.MoO3/Al2O3 afforded a complete degradation of chlorpyrifos with half life of only 3 minutes which otherwise was 24 minutes in the presence of MoO3/Al2O3. The complete mineralization of chlorpyrifos was confirmed by GC/MS analysis, where no peaks of intermediates were recorded. The prepared material also exhibited good recyclability without any leaching of Zn and Mo metals. Thus, ZnO.MoO3/Al2O3 is an efficient and cost effective material for removal of chlorpyrifos. Its potential may also be explored for the removal of other hazardous organic pollutants.