The Synthesis Of TiO₂Nanomaterials In Lamellar Liquid Crystal And Study Of Catalysis Performance

Lamella liquid crystal has characteristic of anisotropy and easy to be adjusted andcontrolled, which promotes intensive study of preparation of nanomaterials templatedby lyotropic liquid crystalline. TiO₂nanomaterials with controllable size andmorphology were prepared in lamella liquid crystal phase in this work. Polarizationmicroscope （POM） and small angle X-ray scattering （SAXS） were used fordetermining the phase structure of lyotropic liquid crystal. The produced sampleswere characterized by X-ray diffraction （XRD）, fourier transform infraredspectrometer （FT-IR）, transmission electron microscopy （TEM）, scanning electronmicroscopy （SEM） and their photocatalytic performance were tested usingdegradation of dye Rh-B as model reaction.TiO₂nanoplate and mesoporous microsphere have been successfully synthesizedusing CTAB as the capping agent in the lamellar liquid crystal consisted ofTritonX-100and TiOSO₄aqueous solution by direct precipitation method andhydrothermal method, respectively. The effect of reactant concentration andCTAB/TX-100mass ratio on the morphology and size of the products were studiedsystematically. The photocatalytic activity of TiO₂samples was evaluated by thedegradation of dye Rh-B. A possible formation mechanism was proposed.TiO₂nanomaterials were prepared using TiOSO₄as reactant, NH3·H₂O asprecipitator by homogeneous precipitation method and lyotropic liquid crystal as softtemplate, which was formed by CTAB/n-C₅H₁₁OH/H₂O ternary system. The effect ofreactant concentration on the shape and size of the samples was investigated andresults show that TiO₂with specific shape can be obtained by adjustment of thereactant concentration.The rigid lamellar liquid crystal, which is ternary multicomponent systemcomprising TX-100, n-C6H12OH, TiOSO₄aqueous solution, and cyclohexane （C6H12）can be formed in a microemulsion system. TiO₂nanomaterials have been synthesizedusing this LLC as template by homogeneous precipitation method. The results showthat the reactant concentration and O/W volume ratio have an effect on the morphology and size of the products. The formation mechanisms of different shapesamples were discussed.A novel, simple and effective method to prepare TiO₂nanomaterials withcontrollable size and shape was developed in this work. The structure of lamellarliquid crystal has an important effect on the shape and size of the final products. Thestructure and performance of nanomaterials can be controlled by adjustment of thecomposition of the lamellar liquid crystal. It is expected that this method can be usedto prepare other nanomaterials with specific performance.