Study On The Modification Of Titanium Dioxide And Its Treatment Of Dye Wastewater

With the improvement of people’s living standard,a large amount of dye wastewater is discharged into rivers without treatment,which is hazardous to human health and also affects the survival of aquatic organisms.Titanium dioxide photocatalytic materials are blended into activated carbon,clay and other high surface area materials to design a composite photocatalytic porous material to remove dye wastewater together with adsorption photocatalysis,which not only can overcome the problem of non-renewable adsorption materials and easy to cause secondary pollution,but also improve the photocatalytic efficiency of dyes due to the presence of high specific surface area.However,these materials have limitations and when they are used in dye wastewater treatment,the pores of materials such as activated carbon are easily blocked by organic dye molecules,leading to a reduction in their adsorption efficiency.Ionic liquids are widely used in adsorption and catalysis research as highly conductive materials that can be designed to be stable and environmentally friendly,and their inherent charge and functional group structure can effectively enhance the bonding strength and promote charge transfer.The presence of ionic liquids can promote composite photocatalysts with shorter contact time,better removal efficiency and great development prospects.This thesis proposes to combine TiO₂ with graphene oxide,ionic liquids and other materials with excellent adsorption ability to prepare three photocatalysts with excellent adsorption performance and investigate the process of removing methyl orange（MO）from simulated dye wastewater.1)Graphene oxide（GO）was combined with imidazolium-based ionic liquids（IL）under non-covalent bonding,followed by the preparation of IL/GO-TiO₂ with TiO₂ by solid-state dispersion,focusing on its efficiency in the removal of methyl orange under photocatalytic action.The addition of the ionic liquid effectively enhances the adsorption efficiency.2)PGO-TiO₂/Fe₃O₄（PGTF）was synthesised by functionalising GO with polymeric ionic liquids（PIL）and then compounding it with TiO₂/Fe₃O₄.From the UV diffuse reflectance（DRS）results,the light absorption range of PGTF was extended to over 400 nm and the band gap energy was reduced to 1.92 e V.It was concluded from the experimental results that PGTF showed better dye removal ability under the synergistic effect of adsorption and photocatalysis.3)Acidic ionic liquids with Fe³⁺anion were synthesized to replace the original hydrolysis inhibitor in TiO₂ prepared by sol-gel method.The product Fe-IL/TiO₂ was also established with peroxynitrite（PMS）as a peroxynitrite advanced oxidation system.The presence of iron-based ionic liquids effectively increases the number of crystalline phases of titanium dioxide and promotes the activation of persulfate.The presence of inorganic anions inhibits photocatalytic degradation efficiency,with cl^-being the most effective.