Synthesis of nanosized gadolinium doped zinc oxide and photocatalyticity of chlorophenols under visible light and it's biological applications

The overarching goal of this thesis is to develop an effective and green photocatalyst to replace currently-used reagents for decomposition of organic compound, or oxidization of contaminants or waste waters from pharmaceutical industries. These commercially available reagents include Fenton's reagent (solution of H202 and Fe2+ catalyst), advanced oxidation processes (A0Ps) and titania (Ti02). However, the requirement of ultraviolet and limited thermal stability of peroxide hinders the application of these photocatalysts. Therefore, it is critical to generate a new photocatalyst to improve oxidation degradation of pharmaceutical waste with zero or near zero harmful byproducts and wide absorbance of solar spectrum, respectively. The thesis proposal aims to demonstrate the photocatalytic degradation of chlorophenols (C61-14C1OH) and its derivatives, the most harmful water pollutant, using gadolinium doped zinc oxide (Gd.,Zni3O) as a catalyst. Gd is chosen due to its unique magnetocaloric effect, which mitigates the secondary contamination of water. Our preliminary research data indicated that lanthanide doped Ln,Zni_.,0 can serve as a more efficient photocatalyst in degrading chlorophenols than the undoped ZnO. It is hypothesized that the insertion of Gd into the ZnO lattice will result in an increase of the photoluminescence property of the catalyst and thus enhances its photo degradation activity. The green and cost-effective sol-gel method will be used to produce nanostructured GdZnj.O photocatalyst applied for pharmaceutical waste treatment. Nano-characterization will be implemented by scanning and transmission electron microscopy to evaluate the morphology and X-ray powder diffraction to determine the crystalline phase structure of these engineered nanomaterials. The photocatalytic degradation of chlorophenol will be measured under direct solar radiation. Various parameters including the initial concentration of chlorophenols, Gd doped ZnO loading and pH of the sample on the photo degradability will be tested to determine the photocataticity of the Gd,Zni0 nanocatalyst