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作者 Charbonneau, Cecile
書名 Aqueous Solution Synthesis of Nanocrystalline Titania Powders: Kinetics, Characterization and Application to Fabrication of Dye-Sensitized Solar Cell Photoanodes
國際標準書號 9780494619773
book jacket
說明 199 p
附註 Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page:
Thesis (Ph.D.)--McGill University (Canada), 2011
The scope of this thesis is the aqueous synthesis and characterization of TiO2 nanostructured powders for the fabrication of thin film photoanodes used in DSC devices. The development and study of this novel process is approached from the standpoint of determining the relationship between the hydrolytic behaviour of isothermally treated TiCl4 aqueous solutions (speciation and kinetics of conversion of Ti(IV) into TiO2(s)) and the properties of the resultant TiO2 products. From an application standpoint, the aqueous synthesized nanocrystalline TiO 2 material is studied for the formulation of screen-printing pastes used in the fabrication of mesoporous photoanodes and resultant dye-sensitized solar cell (DSC) performance
The synthesis of TiO2 nanostructured powders by forced hydrolysis of aqueous Ti(IV) chloride solutions is described in terms of precipitation kinetics and nucleation and growth mechanism over the temperature range 70--90°C and Ti(IV) concentration 0.2--1.5 M. Several techniques are used to characterize the resultant solid products, among which are XRD, FEG-SEM/FEG-TEM, BET surface area, TGA, FT-IR, and EDS analyses. Via appropriate selection of conditions, the aqueous synthesis process is shown that can lead to the preferential production of nanostructured rutile powder with unique self-assembled nanofibre (100 nm -- 3 mum) spheroidal particles or colloids made of well dispersed 4--8 nm crystallites with anatase as the major crystalline phase (85 wt.%). These results are explained and discussed based on the effect of various process parameters (T, agitation), but most importantly based on the pronounced effect of the initial concentration of the TiCl4 aqueous solution on the speciation of the solution and related kinetics of the hydrolysis reaction
When compared to benchmark products such as the P25 TiO2 from Degussa (50 m2/g, 30 nm average crystallite size, very little to no surface -OH/-OH2, and 3.15 eV band gap), the two types of aqueous-synthesized materials are found to possess a high specific surface area, with 80--120 m2/g for the rutile powders and 250--350 m2/g for the anatase powders, enhanced surface hydroxylation, and larger band gap (3.37 eV) in the case of the anatase nanopowder. These materials are shown that can be used for the fabrication of thin film photoanodes prepared by the screen-printing method either separately (i.e. anatase) or as hybrid (anatase-rutile) with the latter being superior in terms of photovoltaic performance. Finally, the direct preparation of paste without drying of the nanocolloids is demonstrated
School code: 0781
Host Item Dissertation Abstracts International 73-02B
主題 Alternative Energy
Chemistry, Inorganic
Engineering, Materials Science
Alt Author McGill University (Canada). Department of Mining and Materials
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