| In this paper, Ti O2 nanomaterials were modified by doped and compound via a sol-gel route, and we have successfully synthesized Tb/tourmaline/Ti O2 composite material with one-dimensional structure, and investigated their electrochemical properties. Ti O2 nanomaterials were not only modified by doped and compound, but also change the morphology to one-dimensional structure, and the photocatalytiv properties of Ti O2 will be also improved. In this dissertation, we synthesized Ti O2 composite materials via a sol-gel route, and studied the effects of the calcinations temperature, the doping of Tb and tourmaline on their crystal form, morphologies and the photocatalytic efficienc. At the same time, we synthesized various quasi-one-dimensional Ti O2 nanomaterials via a hydrothermal route, and studied the effects of reaction temperatures, reaction times and reactant concentrations on their morphologies, crystal structure and photocatalytic efficiency. We have further analyzed growth mechanisms for the different morphology of Ti O2 nanomaterials. We also have systematically studied the tourmaline and Tb how to improve the the photocatalytic efficienc of Ti O2 nanomaterials and the best composite doping of Tb and tourmaline were get. The results show that:(1) Study on the sol-gel preparation process for Tb/tourmaline/Ti O2 composite material when the calcination temperature is 500℃, the best photocatalytic degradation rate of pure Ti O2 is 50.1% and the best photocatalytic degradation rate of Tb/Ti O2 is 75.1%. The optimal dopant amount of Tb was 0.5% and the tourmaline was 0.5wt% by molar of cement and the calcination temperature is 500℃ for the best photocatalytic activity(85.3%). The Tb/tourmaline/Ti O2 sample only has a grain size of 8.9 nm.(2) Ti O2 composite materials were prepared by sol-gel method for improving the photocatalaytic activity. It was found that the catalyst of Tb/doped Ti O2 and Tb/tourmaline/Ti O2 calcined at 500 ℃ is dominated by anatase Ti O2. With the increasing of the calcination temperature, the specific surface are decreased, and the transformation temperature of anatase to rutile; Tb doping retard the growth of crystalline size and the phase transformation from anatase to rutile; Tourmaline compositing retarded the growth of crystalline size but hardly effect the phase transformation from anatase to rutile. The optimal dopant amount of Tb and the tourmalineby molar of cement and the calcination temperature is approproate will improved compared to pure Ti O2 for methyl orange degradation under UV irradiation highly.(3) When the Tb/tourmaline/Ti O2 composite material under high-pressure hydrothermal reaction at 140℃ for 24 h in 10mol/L alkaline solution and then calcined at 500℃, the Tb/tourmaline/Ti O2 nanotube with diameter 5.3nm is obtained. When the hydrothermal reaction temperature was 180℃, the Tb/tourmaline/Ti O2 nanowire with diameter 10 nm is sythrsized. When the hydrothermal reaction temperature was 200℃, the Tb/tourmaline/Ti O2 nanoribbon with diameter 400 nm, thickness 150 nm will be maked.(4) We found that the granularity, size and shape of the products were affected by the temperature, the time of the hydrothermal reation, the concentration of the reactants, the calcination temperature and the doping amount of Tb and tourmaline: With the increase of hydrothermal reation temperature, the trend of the product grow to the multidimensional space; With the increase of hydrothermal reation time, the growth of product is tending towards stability; Product styuture was more easily destroyed with the increase of the calcination temperature; The dopant amount of Tb and tourmaline hardly effect the quasi-one-dimensional Ti O2 nanomaterials.(5) Ti O2 composite materials were prepared by hydrothermal method for improving the photocatalaytic activity of it. It was found that the transformation temperature of anatase to rutile is caused by hydrothermal treatment. Tb-doped retard the growth of crystalline size and the phase transformation from anatase to rutile and enhanc the visible light utilization efficiency and trigger about 50 nm red shift of absorption spectra compar to pure Ti O2.(6) Compared the one-dimensional via a Ti O2 particle hydrothermal route with the Ti O2 particle via a sol-gel route, It was found that the characteristic peak of crystal plane(101) of anatase became intense and the relative intensity enhanced with hydrothermal treatment. Under the action of electric field of tourmaline, the photo-excited electron is absorbed tightly on the anode of tourmaline. Thus, the recombination of e- and h+ is avoided, in addition, the Ti-O-Si of the composites and the coordination of Tb/tourmaline also can improve the photocatalytic properties of nano-Ti O2 effectively.(7) There is a optimum value about the amout of Tb and tourmaline: The highest enhancement in photocatalytic activity is obtained with 0.50% Tb doping. The degradation efficiency declined as the doping concentration of Tb. Because the superfluous Tb only dip on the surface of Ti O2. The highest enhancement in photocatalytic activity is obtained with 0.5wt% tourmaline compositing. The degradation efficiency declined as the doping concentration of tourmaline, too. |
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