tailieunhanh - Phsicochemical Treatment of Hazardous Wastes - Chapter 9

Các phản ứng quang hóa titanium dioxide (TiO2) đã thu hút được nhiều sự chú ý trong lĩnh vực của các quá trình oxy hóa tiên tiến cho hơn 30 năm. Nghiên cứu trên các chất bán dẫn sử dụng xúc tác quang bắt đầu vào cuối những năm 1940 với công việc của Laidler et al, nghiên cứu phản ứng hóa học của oxit kẽm được chiếu sáng. Đồng thời, Mashio và Kato đã nghiên cứu hành động oxy hóa xúc tác quang học của rượu bằng cách TiO2. Vào cuối những năm 1960, Honda và Fujishima đã khám. | 9 UV Titanium Dioxide Introduction The photochemical reactions of titanium dioxide TiO2 have drawn much attention in the field of advanced oxidation processes for over 30 years. Research on photocatalysis using semiconductors began in the late 1940s with the work of Laidler et al. who investigated the chemical reactions of zinc oxide under illumination. At the same time Mashio and Kato were studying the photocatalytic oxidant action of alcohols by TiO2. In the late 1960s Honda and Fujishima made significant discoveries that led to the development of TiO2 as a semiconductor photocatalyst Fujishima and Honda 1971 . The irradiation of a TiO2 electrode coupled with a platinum electrode was found to be able to split water into hydrogen and oxygen Fujishima et al. 1969 the water was simultaneously oxidized and reduced. This discovery laid the foundation for further research on TiO2 to generate hydrogen as a combustible fuel. It soon became apparent that redox reactions of organic and other inorganic compounds could be induced by band gap irradiation of a variety of semiconductor particles. The photocatalytic oxidation of simple organic compounds such as alcohols and carboxylic acids was further studied by Kraeutler and Bard 1998 . Through the 1970s and by the end of the 1980s photocatalytic reactions of TiO2 were studied for almost all classes of organic compounds. In the 1990s a UV TiO2 process for treating wastewaters containing organic pollutants was commercialized. Titanium dioxide is widely used in the production of plastics enamels artificial fibers electronic materials and rubber Hadjiivanov and Klissur-ski 1996 . Its ability to photocatalyze the oxidation of organic materials has been known for years in the paint industry. For this reason TiO2 is used as a white paint pigment Stafford et al. 1996 . TiO2 is also known as an excellent catalyst for semiconductor photocatalysis due to its nonselectivity for environmental engineering applications it is nontoxic .