Study On The Synthesis Of TiO₂-based Photocatalyst, The Active Bleaching Clay Loading And The Application

Semiconductor photocatalytic oxidation is a good to environment technology which enjoys good potential in the field of water treatment applications. What is more, its modification, application, and loading are one of the hottest areas of research in the area of chemistry and material widely in recent years. The papers aims at resolving the contradiction between the immobilization and the activity of TiO₂ photocatalysts in the practical applications, and then the active Nano-TiO₂ was synthesized via Sol-Microwave process, and the powder was modified by rare-earth and transition metal, and synthesized TiO₂ loading activated clay composite photocatalyst, inspect preparation conditions on the physical structure and catalytic properties of the light. On the above basis, the writer comes to the conclusion that it is useful to apply the photocatalytic property to the model pollutant methyl orange solution and the actual degradation of industrial wastewater treatment. The paper consists of the following sections:Using Ti(n-OC4H9)4 as the precursor, acetic acid as the hydrolyzed inhibitor and ethanol as solvent to synthesize Nano-TiO₂ via Sol-Microwave process, and optimized the process conditions of synthesis, the best conditions are as follows: acid water ratio 7:1, microwave temperature 150℃, microwave time 8 min.The doping of La³⁺,Nd³⁺,Eu³⁺,Gd³⁺,Y³⁺ can inhibit the growth of TiO₂ grain, caused the distortion and expansion of the TiO₂ lattice, as well as the absorption edge of the red shift and the range of optical absorption of TiO₂ broaden. The appropriate amount of La³⁺,Nd³⁺,Eu³⁺,Gd³⁺ and Y³⁺ doping can improve the photocatalytic activity of TiO₂, and the best volume-doped are 0.1 %,0.1 %,0.3 %,0.2 % and 0.1 % respectively. Compared with the single-doped system, because of the incorporation of the two ions produced a synergy, the dual system of rare earth co-doped TiO₂ can better promote the photogenerated electron-hole pair separation, and further improve the catalytic activity of TiO₂. Co-doped TiO₂, the best volume-codoped of La/Eu/TiO₂, La/Y/TiO₂ and La/Cd/TiO₂ are 0.1 %-0.3 %,0.1 %-0.5 % and 0.1 %-0.4 % respectively; the best volume-codoped of Eu/La/TiO₂, Eu/Y/TiO₂ and Eu/Cd/TiO₂ are 0.3 %-0.1 %,0.3 %-0.3 % and 0.3 %-0.3 % respectively. The experimental results show that the best in their respective doping, the La/Eu/TiO₂ photocatalyst with a relatively high photocatalytic activity.Zhidan County of Yan'an, Shaanxi Province, is rich in natural clay, which will be easy with the structure of layered microporous activated. Then to use it as a carrier to support the synthesized load of TiO₂ compound photocatalyst, and inspect the load and heat treatment temperature on the complex catalyst structure and photocatalytic properties of the law, and study their recycling. When the TiO₂ loading of 70 %, calcination temperature of 400℃, rare earth elements La and Eu-doped concentration of 0.1 % and 0.3 % of the composite photocatalyst has better performance in treatment of cigarette factory on the industrial wastewater, and good settlement, easy recycling, reuse 3 times, wastewater COD removal rate is still as high as 70 %.