Preparation And Photocatalyst Activity Of TiO₂ Composite Materials Containing Tourmaline Powders And Rare Earth

Based on the natural polarity and far infrared of tourmaline, the unique characteristic of rare earth and photocatalytic properties of TiO2, a kind of novel TiO2 composite sol containing tourmaline particles and rare earth was prepared. Then composite films and nano-powders were obtained by sol-gel process. The preparation technology, microstructure, growth mechanism of crystal, photocatalystic activities and so on were investigated. The effects of tourmaline on the system containing TiO2 and rare earth were determined by testing the conductivity, O2 solved in the water and surface tension of the water under the action of tourmaline. The main conclusions are as follows:(1) The proper process and parameters of the composite powders and the composite films are determinate.(2) TiO2 composite films containing tourmaline and rare earth are prepared by a sol-gel method on the stainless steel sheets and the stainless steel web. The former mainly contains lots of balls whose average particle size is 2 urn and honeycomb, in which the balls are made of needle substance. The latter mainly contains lots of balls whose average particle size is 2 μm, too. The composite catalysts have good photocatalysis, which can degrade effectively methyl orange and formaldehyde and so on.(3)The coordination of tourmaline, rare earth and TiO2 can enhance the photocatalyticactivities of TiO2: When RE/TiO2 composite films containing tourmaline are under UV irradiation, Ce4+ in the films comes into being CeO2-TiO2 system which is just like inserting new energy level. Hence, the spectrum responding range will be extended and the photocatalytic efficiency will be enhanced. Under the action of electric field of tourmaline, the photo-excited electron is adsorbed tightly on the anode of tourmaline. Thus, the recombination of e- and h+ is avoided. With combinative effect of far infrared and electric field of tourmaline, the ionization course of water is accelerated , which is favorable for the forming of ·OH. Consequently, the efficiency of photocatalytic action is enhanced.