An Efficient Photocatalytic Degradation Of Quinalphos Pesticide Under Visible Light Using Zinc oxide/Magnesiun oxide Nanocomposite as a Novel Photocatalyst

Abstract

About one million tons of pesticide effluents were discharged into natural streams and water bodies from local industries and agricultural fields. In view of growing environmental issues there is a requirement for the termination of pesticides and its residues from local and commercial water streams. Photocatalytic degradation method is regarded as a convenient method for the treatment of organic contaminants because of its low cost, lack of secondary pollutants and eco-friendly character. In this study an enhanced and visible light effective ZnO/MgO nanocomposite photocatalyst has been synthesized by a wet chemical method using zinc acetate and magnesium chloride as precursor. The prepared sample has been examined to diagnose its structural, morphological, optical and fluorescence properties using XRD, UV-Vis, SEM, EDX, FT-IR and fluorescence spectral analysis. The organophosphorous pesticide, quinalphos, has a wide application worldwide, particularly to control the population of pests. Due to its toxic character it is necessary to eradicate quinalphos and its residues from the environment. The synthesised ZnO/MgO nanocomposite is analysed to degrade quinalphos pesticide under direct sunlight at neutral pH. The photocatalytic performance of ZnO/MgO nanocomposite is examined by loading 4 mg/L of the catalyst in 20 ppm of the quinalphos solution to achieve 98% degradation in forty minutes. Moreover, this nanocomposite could be separated and utilised up to five cycles with no change in its activity.