Anisha Russelraj; Sibmah Stalin; Kirupa Vasam Jino
Abstract
In view of growing environmental issues there is a requirement for the immediate eradication of pesticides and its residues from local and commercial streamlets. Quinalphos is one of the most common organophosphorous pesticide especially used in agricultural fields bring about a great impact in environment ...
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In view of growing environmental issues there is a requirement for the immediate eradication of pesticides and its residues from local and commercial streamlets. Quinalphos is one of the most common organophosphorous pesticide especially used in agricultural fields bring about a great impact in environment thereby affecting the health of aquatic organisms and humans. Among the various type of method that has been implemented, photocatalytic reaction is considered as the most relevant technique for the removal of toxic organic contaminants. In this study, modified TiO2 has been synthesized by doping with Fe, S using a simple one-step sol-gel method. The incorporation of Fe3+ and the distribution of S nonmetal in TiO2 crystal lattice were affirmed by the XRD, SEM and FT-IR analysis. The band gap energy of Fe/S/TiO2 nanocomposite has been narrowed to 2.5eV and its photocatalytic activity was extended to the visible region. Thus Fe/S/TiO2 photocatalyst was employed for the eradication of Quinalphos and the complete mineralization was achieved in 12 min of visible light irradiation and it is analyzed by TOC analysis. Furthermore, the reusable feature of the catalyst was demonstrated to be utilised for twelve cycles. The penetration of pesticide residues on protein pockets of fishes was predicted by molecular docking. Furthermore, the reduction in toxicity level of the effluent was examined by using aquatic organisms. Thus Fe/S/TiO2 nanocomposite is an efficient photocatalyst to oxidize emerging organic contaminants due to its high synergetic effect of visible light absorbing tendency and low recombination effect of charge carriers.
S. Sibmah Stalin; E.K. Kirupa Vasam Jino
Abstract
This present study involves the sonochemical and microwave synthesis of an efficient light harvesting nanocomposite photocatalyst, ZnO/GO embedded with copper nanoparticles. The synthesised nanocomposite was characterised by various spectroscopic methods like XRD, SEM, EDX, FT-IR, UV-DRS and fluorescence ...
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This present study involves the sonochemical and microwave synthesis of an efficient light harvesting nanocomposite photocatalyst, ZnO/GO embedded with copper nanoparticles. The synthesised nanocomposite was characterised by various spectroscopic methods like XRD, SEM, EDX, FT-IR, UV-DRS and fluorescence analysis. The catalytic activity of the synthesised nanocomposite was tested using an organophosphorous pesticide, as the test solution and its percentage efficiency of degradation were studied. About 99 % of 40 ppm of Quinalphos pesticide could be degraded using ZnO/Cu/GO nanocomposite (3 mg/L) under visible light radiation within20 min at neutral pH. The presence of an intrinsic defects and the fluorescence property of the prepared nanocomposite were also detected. The degradation efficiency was estimated by COD and TOC measurements. The reaction rate followed pseudo - first order kinetics with a rate constant of 0.042 min-1. Furthermore, the composite has demonstrated a reusable feature and was utilised for eight cycles without any change in its activity. These findings has illustrated an ecofriendly, more stable and well organised photocatalytic nanocomposite, which could be preferred much for the treatment of industrial and agricultural waste water containing organic contaminants within a short span of time under irradiation using sunlight.
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