Preparation Of TiO₂/clay Nanocoposite And Application For Photocatalytic Degradation Of Methyl Orange

Photocatalytic degradation method is an advanced waste -water treatment technique. It can degrade organic pollutants entirely and without secondary pollution. It does not need other materials except for ultraviolet light so that energy and materials consumption can be decreased. And the technological process is simple. So it is a prospective wastewater treatment technique. During the past years, the semiconductor photocatalytic process has been applied more and more in wastewater treatment, new energy exploitation, air purification and organic synthesis. Lots of researchers have proved that a great deal of the most organic pollutants can be destroyed by photocatalytic degradation technique. Now, the research of theory and practice about this technique is becoming one of important advanced tasks in environment engineering. In this paper, the active nanoscale TiO2/kaolin composite photocatalyst was synthesized and characterized. The effects of preparing conditions such as calcination temperature on the physical characteristics and the photoactivity were investigated. Moreover, the photodegradation of MO was also discussed in detail.Nano titanium dioxide suspension in the liquid when treating waste water can not be recovered easily, leading to secondary pollution. TiO2/clay nanocomposite is characted as cellularity and superficial, and can be exploited repeatedly and economically when it takes the form of the bulky grain. In this paper, was carried out research on the preparation nanocomposite by the acid-catalyzed sol method of TiO2, and something about the photocatalysis of TiO2. X-ray diffraction tells us that on the surface of kaolin film has formed but it's crystal form is not good. Through infra-red spectum, we know that the band of Si - O- Si has shifted but we do not find Si - O - Ti band. By high resolution transimission electron microscope, we only find TiO2 on the base surface of a small part of kaolin. Nano titanium dioxide is adsorpted on the edge and edge angle of kaolin mainly. More and more TiO2 form aggregates, some of which have not been adsorpted on the kaolin, but the most have adsorpted on the surface of kaolin, not only on the side and edge, but also on the base plate. In the TiCVkaolin nanocomposite which coated with TiO2 4 times, some of the TiO2 aggregates do not attach to the surfaceof kaolin. Some of the kaolin's structure have been damaged and some of the Al has dissolved.The nano titanium dioxide composite which has been produced by us can degrade methyl orange effectively. Through the research of influencing factors, we know that TiO2 has the optimum degradation effect when pH is 2, the concentration of methyl orange is 20mg/L and the addition of photocatalyst is 5g/L. These results help us to find the way to improve the efficiency of the photocatalytic reactions.