Dissertation > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials

Preparation of TiO2 Composite Films and Their Photoelectrochemical Properties

Author WangChunTao
Tutor ZhangWenKui;HuangHui
School Zhejiang University of Technology
Course Industrial Catalysis
Keywords Nitrogen - doped titanium dioxide Composite film Photochromic Optical energy storage Photocatalytic Properties
CLC TB383.2
Type PhD thesis
Year 2012
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Titanium dioxide (TiO 2 ) chemical stability, resistance to light corrosion, non-toxic and low cost, has broad application prospects in the photoelectric conversion and photocatalysis. However, TiO 2 of the larger band gap can only be wavelength less than 387 nm in the UV excitation, photo-generated electrons and holes easy to complex, limiting its application in the field of photoelectrocatalysis. Therefore, the development of efficient visible light response characteristics TiO 2 photocatalyst and expand its field of application is the photocatalytic important tasks. For the TiO 2 light catalytic exist in the field, this paper in order to improve the the TiO 2 of photocatalytic activity in the photoelectric conversion efficiency of research objectives, the use of nitrogen-doped modified TiO 2 photocatalyst NiO film composite prepared by the ITO / TIO << / sub> sub> 2-x n x / NiO composite thin film electrode. Titanium anodizing prepared TiO 2 nanotube arrays were filled tube CdS and Ni (OH) 2. Preparation of TiO 2 / CdS and TiO 2 / Ni (OH) 2 composite film. Using SEM, XRD, XPS and UV-Vis, etc. The samples were characterized, and photoelectrochemical properties of the composite films were studied systematically, following results were obtained: 1, respectively, by the sol - gel and magnetron sputtering two ITO conductive glass as the substrate, the preparation of nitrogen-doped titanium dioxide thin film (TiO << / sub> sub> 2-x N x ), and then using the chemical deposition method TiO << / sub> sub> 2-x the N x films deposited porous NiO films prepared ITO / TIO << / sub> sub> 2-x N x / NiO composite film has better optical the photochromic features and light energy storage capacity. By sol - gel Preparation of nitrogen-doped to TiO << / sub> sub> 2-x N x film molar ratio and heat treatment temperature on TiO << / sub> sub> 2-x N x thin-film photovoltaic performance. Study found the prepared TiO << in different molar ratios (urea and Tetrabutoxide of) / sub> sub> 2-x n x optical catalyst absorption edge red Move 450 6 00 nm range, especially in the molar ratio of 4 samples, the most obvious. Heat treatment temperature on the performance of TiO 2-x N x Thin Films, 400 ° C treated ITO / of Titania 2-x N made with NiO Complex the ITO / TiO , 2-x N x , x / NiO composite thin film electrode, in the light of reversible discoloration characteristics of the film changes color from colorless to brown, 400 nm at the transmittance change reaches 50% of 100 nA discharge time was 4.2 h. Prepare nitrogen-doped TiO 2-x N x film, the gas flow ratio of 1:2 and the heat treatment temperature is 400 ° C conditions prepared using magnetron sputtering TiO 2-x N x film and ITO / of TiO 2-x N x / NiO bilayer films has excellent photocurrent response and Electrophosphorescence of color characteristics. After 1 h irradiation of the sample at the wavelength of 500 nm light transmission change rate of 82%, 100 nA current discharge, the discharge time of approximately 11.1 h, indicating that ITO / TiO 2-x N x / NiO double-layer film having excellent photoelectric conversion characteristics and storage characteristics of the light energy. In the TiO 2-x N x film surface chemical deposition method NiO film has a porous structure, is conducive to the migration of photo-generated carriers and electrolyte impregnated, light process, TiO 2-x N x excited by light generated holes will be the NiO oxide more expensive NiOOH film changes from colorless to brown, which can light charging and photochromic role. 2, using micro-shaped anodized prepared TiO2 nanotube arrays, and composite electrode was prepared by Catalyzed by CdS/TiO2 light alternating deposition method, different media and techniques of TiO2 nanotube arrays, and CdS/TiO2 photocatalytic composite electrode impact of the appearance and photoelectrocatalysis characteristics. The study found that titanium plate as an anode in NH4F and Glycerol Aqueous Solutions prepared aligned nanotube arrays, of tube diameter 50 1 00 nm, wall thickness of about 10 nm, the nanotube is about 1μm. CdS deposition on the TiO2 nanotube arrays state and microstructure is closely related to the deposition time. Composite film electrode prepared CdS/TiO2 under light irradiation in the UV-Vis optical absorption edge of the absorption characteristics of the two semiconductor materials showing absorption edge between 385 and 520 nm, as the deposition time increases, composite optical CdS/TiO2 catalyst tends to increase the absorption edge redshift. The study found that, deposition time for the composite electrode CdS/TiO2 3 min when having the best performance Photoelectrochemical under mercury lamp irradiation target degradation was degradation of methyl orange (MO) is also best performance. 3, electrochemical deposition of Ni (OH) 2 was prepared TiO 2 / Ni (OH) 2 composite electrode deposited TiO2 nanotube arrays, and photoelectrocatalysis, photochromic and optical energy storage in-depth study. The results show that TiO 2 / Ni (OH) 2 composite electrode obvious reversible cause discoloration performance and light energy storage characteristics, after 2 h of light, a current of 100 nA discharge duration up to 19.4 h, showing a good light energy storage characteristics.

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