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771.
采用水热法合成钛酸钾(K2Ti8O17)纳米棒,并将它作为前驱体水热转晶合成TiO2纳米晶,同时通过在水热体系中引入稀土元素La3+实现对TiO2的La掺杂.考察了不同条件下钛酸盐向TiO2的转晶过程,发现水热溶液的pH值、温度以及预处理步骤对转晶过程有很大的影响.利用X射线衍射以及透射电子显微镜对样品的晶相和形貌进行了表征.利用电感耦合等离子体原子发射光谱测量了所合成的La掺杂TiO2样品中的La含量.通过在紫外光下降解甲基橙(MO,10mg/L)测试了La掺杂TiO2样品的光催化性能.结果表明La掺杂后TiO2的光催化活性大大提高.在0.15mol/LLa3+浓度下180oC水热合成的La掺杂TiO2样品显示了最佳的光催化活性.其对MO的光催化降解反应常数高达0.11min-1,大约是空白TiO2样品的9.20倍,P25TiO2的3.69倍. 相似文献
772.
773.
Triethoxysilylpropylamine-capped waterborne polyurethane/titania hybrid films were prepared by in situ method via sol-gel process of titanium n-butoxide under acidic condition. In the paper, we studied the effect of the contents of titania sol on the microstructure, mechanical property, water resistance, and optical property of the hybrid films. It was found, with introducing the content of titania, some physical properties such as tensile strength, modulus, water resistance, refractive index, heat resistance, and ultraviolet absorbance will increase. SEM and SAXS study suggested that the hybrid films had good planarization. 相似文献
774.
通过层层自组装技术, 以结晶的二氧化钛为原料, 在不使用聚电解质的情况下, 免除了高温煅烧, 直接在柔性透明导电基底上制备了全纳米二氧化钛颗粒自组装薄膜。二氧化钛源主要包括带有异种电荷的锐钛矿二氧化钛溶胶和Degussa的P25二氧化钛, 溶胶中的超细二氧化钛纳米晶在制备过程中起到了调节薄膜微观结构的作用, 提高了薄膜的均匀性和致密度。将二氧化钛自组装薄膜作为工作电极, 在三电极体系中进行光电化学测试, 表面均匀致密的二氧化钛薄膜电极表现出了更高的光电化学性能, 加入溶胶后获得的自组装薄膜电极所得到的光电流强度较由全P25组装的薄膜电极提高了近25%。 相似文献
775.
Dr. Jolanda Spadavecchia Dr. Christophe Méthivier Dr. Jessem Landoulsi Dr. Claire‐Marie Pradier 《Chemphyschem》2013,14(11):2462-2469
The mechanism of interaction of Zn porphyrin (ZnPP) with TiO2 surfaces is investigated with a view to optimizing the synthesis of hybrid nanomaterials. The strategy consists of studying the adsorption of ZnPP on TiO2 flat surfaces by taking advantage of complementary surface characterization techniques. Combining a detailed X‐ray photoelectron spectroscopic analysis with AFM imaging allows ZnPP–surface and ZnPP intermolecular interactions to be discriminated. Probing the adsorption of ZnPP on TiO2 nanoparticles (NPs) reveals the dominant role of ZnPP‐mediated interactions, which are associated with the formation of ZnPP multilayers and/or with the state of aggregation of NPs. These preliminary investigations provide a guideline to synthesizing a novel ZnPP–TiO2 hybrid nanomaterial in a one‐step protocol. In this material, ZnPP molecules are presumably involved in the TiO2 lattice rather than on the NP surface. Furthermore, ZnPP molecules preserve their electronic properties within the TiO2 NPs, and this makes the ZnPP–TiO2 hybrid nanomaterial an excellent candidate for nanomedicine and related applications, such as localization of nanoparticles in cells and tissues or in photodynamic therapy. 相似文献
776.
Martin A. Niedermeier Monika Rawolle Dr. Philipp Lellig Dr. Volker Körstgens Dr. Eva M. Herzig Dr. Adeline Buffet Dr. Stephan V. Roth Prof. Jochen S. Gutmann Thomas Fröschl Prof. Nicola Hüsing Prof. Peter Müller‐Buschbaum 《Chemphyschem》2013,14(3):597-602
A low‐temperature route to directly obtain polymer/titania hybrid films is presented. For this, a custom‐made poly(3‐alkoxy thiophene) was synthesized and used in a sol‐gel process together with an ethylene‐glycol‐modified titanate (EGMT) as a suitable titania precursor. The poly(3‐alkoxy thiophene) was designed to act as the structure‐directing agent for titanium dioxide through selective incorporation of the titania precursor. The nanostructured titania network, embedded in the polymer matrix, is examined with atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements. By means of the scattering technique grazing incidence wide‐angle X‐ray scattering (GIWAXS), a high degree of crystallinity of the polymer as well as successful transformation of the precursor into the rutile phase of titania is verified. UV/Vis measurements reveal an absorption behavior around 500 nm which is similar to poly(3‐hexyl thiophene), a commonly used polymer for photoelectronic applications, and in addition, the typical UV absorption behavior of rutile titania is observed. 相似文献
777.
778.
选用两种孔径不同的炭气凝胶CA125和CA500制备了碳含量为20%的TiO2/CA光催化剂,采用X射线衍射、扫描电镜和N2吸附-脱附对催化剂进行了表征,并考察了其光催化降解甲基橙反应性能.结果表明,TiO2/CA样品中TiO2主要以锐钛矿相存在,伴随有少量的金红石相,且均匀分散于炭气凝胶的表面.催化剂的孔隙率分析表明,孔结构直接影响到催化剂的光催化活性,以中孔为主的TiO2/CA125活性要远高于TiO2/CA500.这主要源于中孔良好的吸附性能及其合适的空间限域效应. 相似文献
779.
780.