915 resultados para TiO2


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We report a radio frequency magnetron sputtering method for producing TiO2 shell coatings directly on the surface of ZnO nanorod arrays. ZnO nanorod arrays were firstly fabricated on transparent conducting oxide substrates by a hydrothermal route, and subsequently decorated with TiO2 by a plasma sputtering deposition process. The core/shell nanorods have single-crystal ZnO cores and anatase TiO2 shells. The shells are homogeneously coated onto the whole ZnO nanorods without thickness change. This approach enables us to tailor the thickness of the TiO2 shell for desired photovoltaic applications on a one-nanometer scale. The function of the TiO2 shell as a blocking layer for increasing charge separation and suppression of the surface recombination was tested in dye-sensitized solar cells. The enhanced photocurrent and open-circuit voltage gave rise to increased photovoltaic efficiency and decreased dark current, indicating successful functioning of the TiO2 shell.

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The ZnO/TiO2 core/shell structure was formed through deposition of a TiO2 coating layer on the hydrothermally fabricated ZnO nanorod arrays through radio frequency magnetron sputtering. The effects of the TiO2 shell's characteristics on the current-voltage behaviors of the core/shell-based dye-sensitized solar cells (CS-DSSC) were investigated. As the rates of injection, transfer, and recombination of electrons of such CS-DSSC were affected significantly by the crystallization, morphology, and continuity of the TiO2 shells, the photovoltaic efficiency was accordingly varied remarkably. In addition, the efficiency was further improved by enhancing the surface area in the core/shell electrode.

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一种TiO↓[2]可见光光催化剂的制备方法是将钛醇盐和乙醇反应得到透明液体之后,将该液体滴加到去离子水中,形成白色悬浊液后用无机酸调节pH值,经过超声处理,在80~160℃反应5~20小时,得到TiO↓[2]纳米晶溶胶;将溴化胺按溴化胺滴加到TiO↓[2]纳米晶溶胶中,滴加完毕继续回流反应5~10小时,然后减压蒸发溶剂,得到干凝胶,以乙醇为溶剂对干凝胶抽提萃取,在100~120℃下干燥,得到TiO↓[2]可见光光催化剂。本发明具有操作简单、反应条件温和、设备成本低、较强的可见光吸收和良好的可见光光催化性能等优点。

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一种高折射率纳米晶TiO↓[2]溶胶-凝胶薄膜制备的方法,钛醇盐先进行快速水解,然后用无机酸胶溶,在溶胶-凝胶过程中形成晶相TiO↓[2]纳米颗粒,从而显著提高目标光学薄膜的折射率。本发明具有操作简单、反应条件温和、大面积无规则镀制、设备成本低和光学薄膜折射率高的优点。

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一种用于费托合成重质烃的Co/TiO↓[2]催化剂重量百分比组成为:Co8-15wt%载体85-92wt%所述载体为重量比是ZrO↓[2]∶TiO↓[2]=0-10∶100的物质。提供了控制载体晶相的方法、制备了具有成本低、高性能的费托合成催化剂。

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一种CeO↓[2]-TiO↓[2]复合氧化物载体,其特征在于Ce∶Ti(摩尔比)为0.05-0.4∶1,粒径为1-100nm,比表面积为50-250m↑[2]·g↑[-1],孔体积为0.3-1.2cm↑[3]·g↑[-1],采用一般的混合沉淀、抽滤、洗涤、干燥、焙烧可制成不同比例的水凝胶、醇凝胶、气凝胶CeO↓[2]-TiO↓[2]复合氧化物载体,其特征在于采用钛的无机物为原料,所以大大降低了成本。

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TiO2 nanocrystallites were prepared front precursors tetra-n-butyl titanate (Ti(OC4H9)(4)) and titanium tetrachloride (TiCl4). The precursors were hydrolyzed by gaseous water in autoclave, and then calcined at predetermined testing temperatures. The samples were characterized by X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectra (FT-IR), and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activities of the samples were evaluated by the photobleaching of methylene blue (MB) in aqueous solution and the photocatalytic oxidation of propylene in gas phase at ambient temperature. The results showed that the anatase phase nanocrystalline TiO2 could be obtained at relatively low temperatures (for precursor Ti(OC4H9)4 at I I VC and for TiCl4 at 140 degrees C, respectively), and that the as prepared samples exhibited high photocatalytic activities to photobleach MB in aqueous solution. As the calcination temperatures increasing. the decolor ratio of MB increased and reached the maximum value of nearly 100% at 600 degrees C, and then decreased. The photobleaching of MB by all samples followed the pseudo-first-order kinetics with respect to MB concentration.

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中国科学院山西煤炭化学研究所

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中国科学院山西煤炭化学研究所