Dissertation
Dissertation > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalyst

Synthesis and Characterization of Nanosized Bismuth Complex Oxides as Photocatalysts

Author XieLiJin
Tutor MaJunFeng
School Ocean University of China
Course Applied Chemistry
Keywords Photocatalyst Bi composite oxide Hydrothermal method Reverse microemulsion Low - temperature molten salt method Rhodamine B
CLC O643.36
Type Master's thesis
Year 2006
Downloads 522
Quotes 7
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Environmental pollution and energy shortages are the two major problems facing today's society, how to effectively solve these two problems is the direction of the hard work of many scientists. In many semiconductor photocatalyst materials, TiO 2 its strong oxidizing photoinduced super-hydrophilic, non-toxic and long-term stability in cleaning up the environment important application prospects. However, the TiO 2 photocatalytic material because of its photo-generated electron - hole recombination rate is higher, the larger band gap adverse conditions such as a serious impediment to the promotion and application of photocatalytic oxidation technology. In recent years, in order to solve this problem, many researchers have proposed Bi 2 InNbO 7 , Bi the 4 Ti 3 O 12 , Bi 2 Ti 2 O 7 , Bi 12 TiO < sub> 20 , Bi 2 WO 6 and BiVO 4 and other metal composite oxide containing Bi as visible light response new photocatalysts. However, some of the preparation of the composite oxide because of its inherent defects seriously affect their photocatalytic properties. Therefore, in order to prepare the high activity of the photocatalytic material, we carried out the following aspects of the research work. Bismuth nitrate (Bi (NO 3 ) 3 · 5H 2 O) and butyl titanate (Ti (OC 4 H 9 ) 4 ) as raw material, by controlling the concentration of mineralizing agent, reaction temperature and reaction with potassium hydroxide (KOH) as the mineralizing agent, time conditions, high purity crystalline well-developed, well dispersed, no reunion, size 10 μm the Bi 12 TiO 20 is surrounded by hydrothermal method for the first time prepared crystal microbalance single crystal, the optimum conditions are: [KOH] = 4.5mol / L, reaction temperature of 180 ° C, the reaction time of 4 h. Get of Bi 12 TiO , 20 nano-sized powders, this paper proposes a novel preparation method - isopropyl alcohol-assisted hydrothermal method. Bismuth nitrate (Bi (NO 3 ) 3 · 5H 2 O) and sulfuric acid titanium Ti (SO 4 ) 2 for the raw materials, the reaction temperature was 140 ° C, the reaction time was 1 h, isopropanol concentration of 20vol%, prepare a size of about 10nm and having good crystallinity Bi < sub> 12 TiO 20 nanocrystalline powders, in order to achieve the the Bi 12 TiO 20 nanocrystalline powders of low-temperature synthesis; UV-Vis analysis showed that the synthesized powder has better light absorption properties in the ultraviolet region and the visible region. OP (polyvinyl alcohol nonylphenol ether) as emulsifier, cyclohexane as the oil phase, n-butanol as the promoter, bismuth nitrate (Bi (NO 3 ) 3 · 5H 2 O) and titanium sulfate Ti (SO 4 ) 2 , as the raw material, the use of reverse microemulsion success synthesis of Bi 4 Ti 3 O 12 nanocrystalline powders; using X-ray diffraction (XRD), transmission electron microscopy (TEM) Fourier transform infrared spectroscopy (FT-IR) and UV - visible spectroscopy (UV-Vis) analysis techniques to characterize the samples prepared. The results show that coprecipitation powder synthesized by the method compared with traditional, synthesized by the method not only the size of the powder particles is small, about 35nm and regular shape, uniform particle size distribution in the visible region, it also has good The light-absorbing properties. 3 the bismuth nitrate (Bi (the of NO 3 ) 3 · 5H 2 O) and sodium tungstate (Na 2 WO 4 · 2H 2 O) as raw materials for the reaction of lithium nitrate (LiNO 3 ) and a mixture of nitric acid is satisfied (NaNO3) medium, a mixing ratio of 27:23 (weight ratio), using a low-temperature molten salt method into

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