Preparation Of Mesoporous TiO₂ And Study Of The Catalytic Property

The titanium dioxide (TiO2) is one of important inorganic functional materials, which has unique physical and chemical properties. In recent years, the titanium dioxide is widely used in the fields of solar cell, lithium ion battery, gas sensor, functional ceramic, catalyst, adsorption etc. The previous research indicated that the TiO2 photocatalyst can be used for scavenging air, degrading of the organic matter, pollution abatement, etc.The photochemical catalysis efficiency of TiO2 is a determinant effect for its application. Therefore, how to enhance the titanium dioxide photochemical catalytic activity is a key point of studies on titanium dioxide. The former researches indicate that there are five ways to enhance the photochemical catalytic activity of TiO2, they are:(1) dopes; (2) addition of photosensitizer; (3) loading negative rare-earth element; (4) impulsive-wave activation; (5) increasing surface area of TiO2.The photochemical catalytic activity can be enhanced by increasing the surface area of TiO2. This is because the contact area of TiO2 molecule and adsorbent is enlarged when TiO2 have a large surface area. There are mainly two ways to increase the surface area: the first way is to minimize particle size. When particle size is smaller, it can obtain bigger surface area. Degussa Corporation has produced P25 commercial titanium dioxide powder whose surface area is 50 (±15) m2/g. The second way is to prepare particles with mesoporous structure. In this condition, the surface area increases drastically, consequently the photochemical catalytic activity is enhanced greatly because of the great interior holes in this structure.In this work, the mesoporous TiO2 materials are prepared by hydrothermal process. Afterwards, the influences of different ratio of Ti4+ concentration and heat treatment on the morphologies and crystalline are studied. In addition, the photochemical catalytic activity of mesoporous TiO2 is examined.This work includes two sections.The first section is to obtain mesoporous TiO2 by using titanium sulfate as the titanium source. Then we investigated the influence of different ratio of Ti4+ concentration and heat treatment on the crystalline and morphologies through X-ray diffraction, the scanning electron microscope. Furthermore, the samples are characterized by nitrogen adsorption-desorption isothermal and ultraviolet-absorption spectrum.The second part is to analyze the photochemical catalytic activities of mesoporous titanium dioxide material by the methyl orange solution's degeneration experiment.