COMPARISON OF THE PHOTOCATALYTIC PROPERTIES OF TiO2 NANO-PARTICLES PREPARED BY SOL-GEL AND ULTRASONIC ASSISTED SOL-GEL METHODS

摘要

TiO2 photocatalysts have been widely used as potential catalysts for pollution abatement. However, improving the efficiency of the TiO2 catalysts for the complete photocatalytic degradation of organic and inorganic pollutants within a shorter period of time is still a major challenging factor. Many methods have been employed for the preparation of TiO2 photocatalysts such as hydrothermal, co-precipitation, combustion and including sol-gel methods. It is well known that photocatalytic properties of TiO2 are mainly dependent on the preparation methods and conditions. We have successfully prepared TiO2 photocatalysts by three different methods: sol-gel and ultrasonic-assisted sol-gel methods (bath and tip types). Among the three different methods, bath-type ultrasonic-assisted sol-gel method was able to control all the important parameters of the TiO2 photocatalysts such as particle size, surface area, pore-volume and pore-diameter, which are important factors to control the photocatalytic activity of the catalysts. In this study, the photocatalytic degradation efficiency of the prepared TiO2 catalysts was compared by the oxidative degradation of 4-chlorophenol, which is one of the major pollutants in many industrial wastewaters.