| With the excessive exploitation of natural resources and grave pollution of environment,the deterioration of ecological environment becomes more and more serious.lt is urgent to develop ecomaterials,which use economically energy and have no harm to environment.With its renewal ability and storability of energy and friendliness of environment, nano-semiconductor TiO2 is the very novel green purificant. Now its relevant study becomes the focus of the field of photocatalysis,especially in wastewater treatment. Although nano-TiO, powders can be obtained by many methods such as Sol-Gel process,CVD,chemical deposition, these methods are complex in equiepments,strict in conditions of preparation.As a result,it is difficult to realize its commercialization, the pertinant research work has been carried out as follows:For the first time organic electrolysis-sol-gel process was used for preparing nano-TiO2 powders. Ti(OBu)4, precursor of nano-TiO2 powders was obtained by using C4H9OH and a little organic salt being used as electrolyte,!! paltes as electrodes. Then nano-powders were obtained by sol-gel process.The method succeeded in avoiding the use of expensive materials,serious pollution.The effects of preparation conditions on the photocatalytic activity of nano-TiO, were researched systematically. The proper process and parameter were also determinated. The higher photoactive nano-TiO2 particles were obtained, with specific surface of 170m2/g, d<10nm,in the proper course of following: Ti(OBu)4: EtOH:H2O(mole ratio)=l:(3~5):(2~6), 30-40 *C (Sol-Gel process), and calcining at 400'C under air atmosphere for 3.5 hours. The transmission electronic microscope, X-ray diffraction , TG-DTA analyzer, ASAP2010 surface analyzer (BET), Zetaplus Potential Analyzer are used to study the morphology structure, Variability of the weight and classification, surface size and particle distribution. In the following course of calcining, dry gel powders of TiO2 transfer completely to anatase type TiO2 before 365 "C, and rutile type TiO2 is formed at about 388X^. The corresponding activation energy of anatase crystal growing process during the process of calcination treatment was 26.38KJ.mol'1.The photocatalytic activity of TiO2 doped with single transitional metal oxide was studied systematically. The research results shows that kind doped element and its concentration has great effect on photocatalytic activities of nano-TiO2 particles.There is the best value for every dopant. Over higher or lower dopant concentration decreases photoactivities of nano-TiO2 powders. The Tin oxide as dopant in nano-TiO2 powders can improve obviously the powders, photoactivity and other transition metal oxides are almost inefficient in improving its photoactivity. The reason for the Tin oxide herein lies in the fact it contributes to increment of quantum size effect,formation of doped energy band, and improvement of surfacee OH concentration.Up to now. There is less studies on photocatalytic activity of rare-earth metal oxides doped nano-TiO2 powders. We investigated the influences of the single rare earth oxide doped TiO2 powders on photocatalytic activity.lt was found that rare earth ion,which electronic number on 4f orbit is approximately (K 7 or 14, doped TiO2 had higher photoactivities. By analyzing its XRD. Patterns, It was found that the average grain size of crystallized anatase of Pr2O3> Yb2CV Tm2O3 doped TiO2 powders was respectively bigger than pure TiO2 powders at lower than 400*C for 3.5 hours. It showed that the lattice of anatase type TiO2 doped becomed into aberrant and expansive, at above 400癈 for 3.5 hours, its nanocrystalline size was significantly smaller than pure TiO2 powders. And the proportion of rutile phase is less too. It showed that the expensive lattice of rare earth oxides doped TiO2 powders can hamper the growth of rutile type TiO2.Futhermore, on industrial aspect, We explored the applicable possibility of rare earth doped nano-TiO2 films for degradation of phenol in water. Immobilized on scum Ni net, stainless ne...
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