visible light, Er ~ (3 +)-Yb ~ (3 +) and Er ~ (3 +)-N co-doped upconversion nanocrystals TiO_2 photocatalytic properties

Title: visible light, Er ~ (3 +)-Yb ~ (3 +) and Er ~ (3 +)-N co-doped upconversion nanocrystals TiO_2 photocatalytic properties
　　Author: Nana Zhao
　　Degree-granting units: Northeast Normal University
　　Keywords: Er ~ (3 +)-Yb ~ (3 +) co-doped nano-TiO_2;; Er ~ (3 +)-N were doped TiO_2;; photocatalysis;; conversion
　　Summary:
　　TiO_2 as a photocatalyst with a chemically stable, cheap, non-toxic, high efficiency catalysts have broad application prospects. However, currently TiO_2-based photocatalytic technology, there are still low quantum efficiency, solar energy is low, the use of UV degradation Neodymium Magnets requires a lot of energy and other technical problems, thus limiting the application of TiO_2 photocatalytic method. In this paper, nano-titanium dioxide as a substrate by doping rare earth ions and non-metallic elements, the use of rare-earth ion upconversion luminescence and absorption of visible light and then emit ultraviolet light, visible light to achieve the degradation of organic compounds using titanium dioxide to the purpose. Specific tasks are as follows:
　　1 sol - gel synthesis of Er ~ (3 +)-Yb ~ (3 +) co-doped TiO_2 nanocrystals synthesized by hydrolysis precipitation method Er ~ (3 +)-N co-doped nanocrystalline TiO_2 .
　　(2) the use of XRD, BET, TEM, SEM, AFM, UV-Vis and photoluminescence spectroscopy and other means, for the synthesis of Er ~ (3 +)-Yb ~ (3 +), Er ~ (3 +)-N co-doped nanocrystalline TiO_2 a systematic characterization.
　　3 of the Er ~ (3 +)-Yb ~ (3 +) co-doped nanocrystalline TiO_2 of methyl violet in the visible light photocatalytic degradation was investigated at different calcination temperature (900 ° С, 950 ° С , 1000 ° С and 1050 ° С), initial concentration of methyl violet, light amount of catalyst and different pH values ​​of photocatalytic degradation of methyl violet case raised issues related to the conversion photoluminescence, energy absorption and transfer, photosensitizing dye photocatalytic mechanism of such processes.
　　4 of the Er ~ (3 +)-N co-doped nanocrystalline TiO_2 of methyl violet in the visible light, the photocatalytic degradation of phenol, the same influence of different calcination temperature (400 ° С, 500 ° С, 700 ° С and 900 ° С), the amount of http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets N-doped photocatalytic degradation such as the impact of the degradation process dynamics, re-use of catalyst effect.
　　In short, the preparation of the two photocatalysts under visible light can be achieved in organic dyes and photocatalytic degradation of organic pollutants, the degradation efficiency reached 93.3% and 95.6%, the photocatalytic effect is much larger than the undoped TiO_2, this work to further expand the field of nano-TiO_2 photocatalytic applications, especially in the visible light degrades organic pollutants is of great significance.
　　Degree Year: 2010