Citrullus lanatus Mediated-green Synthesis of Ag/ZnO Composite for Photocatalytic Degradation of 2,4-dichlorophenoxyacetic acid

摘要

Litchi chinensis-like ZnO were successfully synthesized by Citrullus lanatus-mediated sol-gel method. The aqueous extract of Citrullus lanatus fruit rind can be acted as stabilizing and reducing agent in the process formation of ZnO. Scanning electron microscopy showed that the as-synthesized ZnO were accumulated by many small particles and formed litchi chinensis-like structure. X-ray diffraction and fourier-transform infrared spectroscopy analyses proved that the as-synthesized ZnO were highly crystalline with the wurtzite structure. The Ag decorated ZnO photocatalysts (Ag/ZnO) were also synthesized to enhance the photocatalytic activity. Under sunlight irradiation, Ag/ZnO demonstrated higher photocatalytic activity towards the degradation of 2,4-dichlorophenoxyacetic acid compared to that of ZnO. The photocatalytic enhancement of Ag/ZnO could attribute to the effective charge carriers separation which could helps to increase the reactive radicals quantities. The observed results exhibited the potential of photocatalytic technology in purifying wastewater over Ag/ZnO composites.