Preparation And Catalytic Performance Of The New Photocatalytic Materials

The water pollution today, caused by hazardous organic chemicals used in industry and agriculture, is a very serious problem. There has been a great effort and there is a number of ways to devote into the treatment of wastewater. Over the past 20 years, the scientific and engineering interest in the semiconductor photocatalysis has grown exponentially because the photocatalytic reactions allow in many cases a complete degradation of organic pollutants in very small and not noxious species, without using chemicals, avoiding sludge production and its disposal. TiO₂ in the crystalline form of anatase has been widely used due to its high photostability, innocuity and low cost. Until now, there are still some serious problems, which hinder the application of TiO₂ in the industry, such as the low quantum production, and the convenience of catalyst immobilization on progressively large particles is bought at the expense of increased average convective-diffusion distance from fluid to catalyst surface.To resolve the problems stated above, this thesis researches on the support, modification of TiO₂ photocatalysts, and its performance under UV and Visible light irradiation. A new series of photocatalysts nano Alkali Titanate were also researched.In chapter 1, TiO₂ photocatalysts have been reviewed, including the principles and mechanisms of photocatalysis, environmental applications, the lattice and electronic structure of TiO₂, its surface modification and immobilization of photocatalysts.In chapter 2, some science aspects in the experimental process of supported catalysts have been represented, such as the classification and the selection of supporter, the connection between the supporter and active component and the preparation method of supported catalysts.In chapter 3, nano TiO₂ particles deposited on crude nonmetallic minerals were prepared by a Sol-dipping process, the photocatalyst for degradation of chloroform was tested, and optimized with respect to TiO₂ loading, catalyst dosage, calcinations temperature and pH value of the initial wastewater. The adsorption properties and...