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Preparation and Properties of Stable Nanocrystalline Anatase TiO 2 Colloids
Author(s) -
Chen X.Q.,
Shen W.H.
Publication year - 2008
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.200700450
Subject(s) - anatase , nanocrystalline material , colloid , photocatalysis , materials science , chemical engineering , dynamic light scattering , zeta potential , rhodamine b , particle size , analytical chemistry (journal) , chemistry , nanotechnology , chromatography , nanoparticle , organic chemistry , engineering , catalysis
The nanocrystalline anatase TiO 2 colloid has widely been applied in solar energy conversion, photo‐degradation of organic pollutions, photochemical disinfection, processing of sensors, and papermaking. It can be obtained from the hydrolysis of titanyl organic compounds [TiO(OOCCH 3 ) 2 and Ti 2 O(OC 4 H 9 ) 2 (OOCCH 3 ) 4 ] at low temperature and normal pressure. TEM (Transmission Electron Microscope), SEM (Scattering Electron Microscope), and LS (Layer Scattering) analysis showed that the colloidal particles are spherical and possess a narrow size distribution, that the mean size (80 °C, 2 h, sample B) is 8.9 nm and its isoelectric point is 6.67. The S BET of the gel powders are 262.7457 m 2 /g (60 °C, 2 h, sample A) and 258.0024 m 2 /g (80 °C, 2 h, sample B). Research experiments showed that the turbidities of colloidal solutions decreased along with the decrease of water content in the mixed water‐alcohol dispersants, which predicated that the colloidal stability fell when lowering the electrical conductivity of the dispersant. The zeta potentials of the colloids are 14 mV ∼ 30 mV at pH 4.5 ∼ 6.0 in the presence of 0.5 · 10 –2 mol L –1 NaNO 3 electrolyte. Furthermore, the UV absorbance of the nanocrystalline TiO 2 colloidal solutions increased with a decrease in particle size. The experimental results of photocatalytic degradation of the dye rhodamine revealed that the nanocrystalline TiO 2 colloidal particles from this preparation method have good photocatalytic activity, which is better if doped with 0.2 % Fe 3+ .