| 鈽匱itania and titanate photocatalysts, which are nontoxic, insoluble, have a good prospect in dye wastewater treatment. Moreover, titanate nanotubes exhibite desirable properties for their applications in Lithium-ion-battery, electrochemical capacitors, solar energy conversion. The unique properties of nanoparticles are highly dependent upon preparation methods. A Simple titanium resource and a soft preparation method is very important in the preparation of titania, hydrogen titanium oxide hydrate and sodium titanate. In this study, by solvothermal method, TiO2 nanoparticles and H2Ti2O5路H2O, Na2Ti2O4(OH)2 nanobutes were synthesized. The formation mechanism of the nanomaterials was discussed and their photocatalytic activity in the degradation of active Brilliant-blue dye solution was investigated. Here follows the main contents of the paper.鈽?. When pH<8, the Ti(OH)4, which were the hydrolyzed tetrabutyl orthotitanate, were intended to decompose to form TiO2 nanoparticles under a high pressure conditions.Here were the best preparation conditions for TiO2 nanoparticles: the pH values was lower than 8, the molar ratio of tetrabutyl orthotitanate to stearic acid was 2:1, the concentration of the tetrabutyl orthotitanate was 15%, the reaction time was 12 and the reaction temperature was 120鈩?or 130鈩? And when the reaction temperature was 180鈩? the TiO2 nanoparticles were intended to form nanospheres by Self-Assembly.鈽?. When the reaction time was 24h, the pH value was 9-10, all of the samples were assigned to H2Ti2O5路H2O, and for the Na2Ti2O4(OH)4, the pH value was 12-13．The high temperature was good to a high crystalline nanotubes. In the solvothermal reaction system, sheetlike structures of H2Ti2O5路H2O(or Na2Ti2O4(OH)2) were firstly formed. Then the driving force or the curling of sheetlike structure came from the thermal stress existing at high pressure, which reduced the interlayer forces at the edges and scrolled the sheets into tubes.鈽?. At the beginning of the reaction, as the stabilizing agents and the surfactant, stearic acid gave the premise for the forming of the nanomaterials. During the reaction, stearic acid, which absorbed around the surface of Ti(OH)4, acted as the microreactors, which offered the good circumstances for the forming nucleation and crystallization.鈽?. The FTIR of different catalysts showed that there were many hydroxyl groups. The UV-vis spectra of them showed that the maximum absorption boundaries of TiO2 nanoparticles (457nm), H2Ti2O4(OH)2 nanotubes (425nm), Na2Ti2O4(OH)2 nanotubes (400nm), were all red-shifted relative to the bulk anatase TiO2(387nm) and the absorption intensity for the samples was: TiO2>H2Ti2O路H2O>Na2Ti2O4(OH)2,which indicated that photocatalytic activity of them may be TiO2>H2Ti2O5路H2O>Na2Ti2O4(OH)2．鈽?. The degradation rate curves of dye solution with different catalysts showed that after 6 hrs irradiation, the photocatalytic degradation rate of the active Brilliant-blue (KN-R) were 80%(TiO2 nanoparticles), 76% (H2Ti2O4(OH)2 nanotubes) and 55% (Na2Ti2O4(OH)2nanotubes) and the photocatalytic activity of the samples was: TiO2>H2Ti2O5路H2O>Na2Ti2O4(OH)2> the bulk anatase, which was in good accordance with the fact of UV-vis absorption spectra.鈽?. The radicals and the hydroxyl groups play a key role in the degradation process and the more radicals or hydroxyl groups means the better photocatalytic activity. In our study, the synthesized three catalysts had some hydroxyl groups, which mean the samples had a promising prospect in photocatalysis. The red-shifted maximum absorption boundaries of the samples mean that the samples can absorb more photons under UV light or sunlinght. Thenc the red-shifted maximum absorption peaks of three catalysts mean a better photocatalytic activity.
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