Ti(IV)在介孔氧化硅MCM-41中的液相移植

以钛酸丁酯为原料,通过液相移植反应,在介孔氧化硅ＭＣＭ－４１中成功地组装了Ｔｉ（ＩＶ）,利用ＸＲＤ、ＴＥＭ、ＥＤＳ、ＦＴ－ＩＲ、Ｎ_２吸附－脱附、^２９Ｓｉ ＭＡＳ ＮＭＲ等多种实验方法对材料进行了表征,并讨论了液相移植反应的机理．实验表明,通过与介孔材料骨架表面Ｑ^３硅原子中的硅醇键（Ｓｉ－ＯＨ）的反应而形成钛－氧－硅（Ｔｉ－Ｏ－Ｓｉ）键,Ｔｉ（ＩＶ）被成功地固定到介孔材料的骨架上面; ９５０～９６０ｃｍ^－１红外共振吸收的加强是Ｓｉ－Ｏ－Ｔｉ键形成的标志．     

TiO_2在MCM-41内表面单层及双层分散的结构表征

首次以有机物钛酸丁酯为前驱体,合成了ＴｉＯ２呈单层分散状态（Ｔｉ／Ｓｉ＝０.２０）或双层分散状态（Ｔｉ／Ｓｉ＝０．３９）的介孔分子筛ＭＣＭ－４１（Ｓｉ／Ａｌ＝３５）,并以 ＸＲＤ,ＦＴＩＲ,Ｎ２吸附－脱附,固体ＵＶ－ｖｉｓ 漫反射等表征手段对其结构特征和氧化钛分散状态进行了研究．结果表明： ＴｉＯ２在介孔分子筛ＭＣＭ－４１孔道中分散, ＭＣＭ－４１骨架结构结晶度降低,但是附着二层ＴｉＯ２后,仍能保持长程有序结构; ＴｉＯ２与ＭＣＭ－４１孔道表面的ＳｉＯ２以化学键连接,生成Ｓｉ－Ｏ—Ｔｉ键;无论是单层还是双层分散的 ＴｉＯ２在 ＭＣＭ－４１内孔壁均匀分散;且由于ＴｉＯ２粒子的减小使其对紫外光的吸收发生明显的蓝移现象．     

纳米Au团簇在氧化钛修饰的介孔分子筛MCM-41中的组装

以钛酸丁酯为ＴｉＯ_２前驱体,使ＴｉＯ_２均匀分散于纯硅介孔分子筛ＭＣＭ－４１的介孔孔道内表面,利用ＴｉＯ_２光学性质将ＡｕＣｌ－４还原为Ａｕ（０）并组装于氧化钛修饰的ＭＣＭ－４１孔道中．对所合成的Ａｕ负载的氧化钛修饰的ＭＣＭ－４１进行了ＸＲＤ,ＸＰＳ,Ｎ_２吸附－脱附曲线,及固体ＵＶ－Ｖｉｓ漫反射等多种结构表征．由ＸＰＳ谱和固体ＵＶ－Ｖｉｓ漫反射吸收光谱的ｐｌａｓｍｏｎ吸收峰证明Ａｕ团簇呈现０价的金属状态．     

硅藻上一莫来石陶瓷负载SiO2膜的制备与表征

将液晶模板技术与溶胶－凝胶法相结合,制备了硅藻土－莫来石陶瓷（Ｋ－Ｍ）负载型ＳｉＯ２膜。表征实验结果表明：ＳｉＯ２膜层与ＴｉＯ２过渡膜层间通过Ｓｉ－Ｏ－Ｔｉ键的价联方式形成了紧密、稳定的伦合型复合膜;ＳｉＯ２膜孔径集中在４～５ｎｍ,孔分布较为均匀;Ｋ－Ｍ负载ＳｉＯ２膜管对气体具有较强的渗透能力,并有较好的气体分离作用根据实验结果探讨了模板剂的性质及用量对ＳｉＯ２膜孔结构的决定性作用。     

六方棱柱结构介孔氧化硅材料的合成及其机制探讨

在强酸性条件下合成了具有六方棱柱结构的介孔氧化硅ＭＣＭ－４１材料,并通过ＸＲＤ、氮气吸附、ＳＥＭ、ＨＲＴＥＭ等手段对材料性能进行了表征。结果表明：在微米尺度上具有六棱柱结构的ＭＣＭ－４１材料,是由定向规则排列的纳米孔道组成,表面附着硅酸根离子的表面活性剂胶束按照液晶几何构造定向聚集生长,是导致六方棱柱结构介孔材料形貌生成的主要原因。     

低表面活性剂/硅比率中有序介孔材料的合成

以ＡｌＣｌ３．６Ｈ２Ｏ为铝源,在低表面活性剂／硅摩尔比的体系中,合成Ｓｉ／Ａｌ比在１６－６４范围内变化的有序介孔硅酸铝材料。用ＸＲＤ、ＴＥＭＦＴＩＲ及氮吸附等测试手段对材料进行了分析。ＸＲＤ分析表明,用铝原子取代硅原将导致晶格增大。     

铅基钙钛矿型结构铁电薄膜的介电及热释电性能研究

用改进的溶胶－凝胶旋转涂履技术,在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ基片上研制出了１－２μｍ厚,具有钙钛矿型结构的ＰｂＴｉＯ３、ＰＬＴ和ＰＺＴ铅基铁电薄膜。该类铁电薄膜具有良好的结晶特性、优异的介电和热释电性能。     

La2O3—TiO2系陶瓷物相与介电性能研究

固相法合成Ｌａ２Ｏ３－ＴｉＯ２系陶瓷介质材料,ＸＲＤ、ＳＥＭ、ＥＤＳ分析其结构、形貌和成分。高精度电容测量仪测试其介电性能。Ｌａ２Ｏ３／ＴｉＯ２比１∶２、２∶１９组分可获得极低介质损耗,ＸＲＤ分析主晶相为Ｌａ２Ｔｉ２Ｏ７和Ｌａ４Ｔｉ９Ｏ２４。Ｌａ２Ｏ３／ＴｉＯ２比１∶３组分可获得Ｌａ２／３ＴｉＯ３、Ｌａ４Ｔｉ９Ｏ２４复相、缺陷型钙钛矿相Ｌａ２／３ＴｉＯ３不利于介质损耗降低。ＥＤＳ分析表明晶界富集Ｓｉ杂质,有效促进了液相烧结。     

TiO2在MCM-41内表面单层及双层分散的结构表征

首次以有机物钛酸丁酯为前驱体,合成了ＴiO2呈单层分散状态（Ｔi/Si=0．２０）或双层分散状态（Ｔi/Si=0．39)的介孔分子筛ＭＣＭ－４１（Si/Al=35）,并以ＸＲＤ,ＦＴＩＲ,Ｎ２吸附－脱附,固体ＵＶ－vis漫反等表征手段对其结构特征的氧化钛分散状态进行了研究,结果表明：ＴiO2在介孔分子筛ＭＣＭ－４１孔道中分散,ＭＣＭ－４１骨架结构结晶度降低,但是附着二层ＴiO2后,仍能保持长程有序结构;ＴiO2与ＭＣＭ－４１骨架结构结果度降低低,但是附着二层ＴiO2后,仍能保持长程有序结构,ＴiO2与ＭＣＭ－４１孔道表面的ＳiO2比化学键连接,生成Ｓi-O-Ti键;无论是单层还是双层分散的ＴiO2在ＭＣＭ－４１内孔壁均匀分散,且由于ＴiO2粒子的减小使其对紫外光的吸收发生明显的蓝移现象。.     

SrTiO3基陶瓷的介电谱研究

采用标准的固相反应法制备成０．９１（Ｓｒ０．８４Ｐｂ０．１６）ＴｉＯ３＋０．０９（Ｂｉ２Ｏ３·３ＴｉＯ２）介电陶瓷（缩记为ＳｒＴｉＯ３基陶瓷），并详细地研究了此种陶瓷的介电谱，即介电温度谱和介电频率谱。由介电谱确定了此种陶瓷的结构相变、居里温度、介电弛豫频率和介电弛豫时间，并对它们进行了讨论。     

Design of single-site Ti embedded highly hydrophilic silica thin films with macro-mesoporous structures

Single-site Ti-containing macroporous silica thin films with mesoporous frameworks were successfully prepared on quartz substrate with high transparency by using poly(methyl methacrylate) (PMMA) microspheres and organic surfactant as template of porous structures. The presence of mesoporous structure and the differences of macroporous structure of film surface were investigated by XRD and FE-SEM measurements. The local structure of Ti moieties embedded within silica matrixes were also confirmed by UV-vis investigations. It was found that the macroporous structure and the embedded single-site Ti moieties within mesoporous frameworks were quite effective for improvement of surface hydrophilicity, i.e., the water droplet was entirely spread on the film surface even before and after irradiation of UV light.     

Preparation and characterization of hexagonal mesoporous titanium–cobalt oxides

Hexagonal mesoporous Co–Ti oxides were synthesized via a supramolecular assembly route, using a non-ionic surfactant, polyoxyethylene fatty alcohol (AEO₉). The textural and electronic properties of the specimens were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high resolution transition electron microscopy (HRTEM) and N₂-physisorption at 77 K. The application of the mesoporous Co–Ti oxides in the catalytic oxidation of cyclohexane was explored.     

合成条件对晶态介孔TiO2结构和性能的影响

采用sol-gel法合成了锐钛矿相介孔氧化钛，利用XRD、BET、TEM和PL对介孔TiO2的结构和光致发光性能进行了表征及分析。结果表明，采用预制TiO2溶胶为钛源，所得介孔氧化钛具有良好的锐钛矿晶型、较大的孔径和比表面积，具有高的光致发光活性。     

氮硫掺杂介孔TiO2薄膜结构及其光催化性能

分别以Ti(OBuⁿ)₄和Pluronic F127为无机前驱体和模板剂, 以硫脲为添加剂, 采用sol-gel法结合蒸发致自组装法（EISA）制备了锐钛矿结构的介孔TiO₂薄膜材料.采用SEM、 XPS、N₂ 吸附-脱吸、XRD和 UV-Vis光谱对其进行了表征. 研究发现, 向前驱体溶液添加硫脲一方面改变了TiO₂的介孔结构, 另一方面对介孔TiO₂进行了N、S共掺杂. 当溶液中硫脲与Ti(OBuⁿ)₄的摩尔比为2.5%时, 介孔TiO₂的孔径由未掺杂的7.0nm增至12.4nm, 光催化降解甲基橙实验表明其在紫外光区具有最优的光催化活性; 当溶液中硫脲与Ti(OBuⁿ)₄的摩尔比为5%时, 其吸收边由380nm扩展至520nm, 光催化降解罗丹明B实验表明其在可见光下显示出最优的光催化活性.     

TiO_2纳米管/介孔SiO_2复合膜的制备及生物活性研究

以表面构筑了TiO2纳米管阵列的金属钛为基底,采用溶胶-凝胶工艺和浸渍-提拉技术涂覆介孔SiO2薄膜,构建了TiO2纳米管/介孔SiO2复合膜。利用SAXRD、FTIR、HRTEM和FESEM等表征样品的结构和微观形貌。研究表明,在高度有序、规整排列的TiO2纳米管阵列基底上,利用溶胶-凝胶工艺和浸渍-提拉技术涂覆有六方相介孔SiO2薄膜的复合膜具有良好的生物活性。     

酸对合成二氧化钛介孔材料的影响

以硫酸和乙酸为酸度调节试剂,采用Sol-Gel过程和水热处理结合,在没有添加任何表面活性剂作模板剂的条件下,通过钛酸丁酯（TBOT）在酸性体系中的控制水解和自组装制备TiO₂介孔材料.产物采用XRD、N₂吸附-脱附等温线、TG-DSC进行分析表征.通过选择酸的种类和控制酸的浓度,添加配位抑制剂TEA减缓Ti的水解速率,可合成介孔纯TiO₂材料.使用硫酸（H₂SO₄∶TBOT＝1∶1,摩尔比）和TEA制备出比表面积为176m²/g,孔容为0.222cm³/g,平均孔径约5nm,孔径分布窄,热稳定性较好的TiO₂介孔材料.     

Transformation of microporous titanium glycolate nanorods into mesoporous anatase titania nanorods by hot water treatment

High surface area titanium glycolate microporous multi-faceted nanorods were synthesized from the reaction of titanium alkoxides (Ti(OEt)₄, Ti(O ⁱ Pr)₄, or Ti(O ⁿ Bu)₄) with ethylene glycol, using a sol–gel reflux method. The specific surface area of the as-synthesized titanium glycolate nanorods obtained from Ti(OEt)₄ is ~480 m²/g. A hot water treatment at 90 °C for 1 h transformed the titanium glycolate microporous nanorods into mesoporous anatase TiO₂ nanorods. The shape of the nanorods was conserved after hot water treatment and the microporous to mesoporous transformation took place without significant change in the surface area (477 m²/g). Micro Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, solid state NMR, and nitrogen adsorption/desorption were used to characterize the samples. As a demonstration of potential applications, the thus formed mesoporous anatase TiO₂ nanorods were tested for their photocatalytic efficiency in the degradation of crystal violet, and a photodegradation mechanism is proposed.     

La掺杂TiO2介孔微球的超声水热合成和光催化性能

以钛酸四丁酯为钛源、硝酸镧为镧源、十二胺为模板剂,采用超声?水热法合成了La3+掺杂介孔TiO2微球,并利用XRD、XPS、TEM、BET、UV-Vis、IR、FL等手段表征了材料的结构、形貌、比表面积、孔径分布及光学性能.研究结果表明,适量La3+离子掺杂不仅能使介孔TiO2晶粒细化,比表面积增大,荧光强度减弱.La3+/TiO2的光吸收边红移,并具有比商业P25更好的光催化活性,其中介孔La3+/TiO2(2.0at%)的比表面积和平均孔径分别为132.7 m2/g和8.67 nm,光催化降解初始浓度为40 mg/L的亚甲基蓝溶液120 min时,其降解率达到98.5%,表现出最强的光降解能力.     

The complex morphologies of Ti-MCM-41 templated by Gemini surfactant

The ordered hexagonal mesoporous materials of Ti-MCM-41 have been synthesized by using the Gemini surfactant bis(hexadecyldimethylammonium bromide)hexane (GEM16-6-16) as template. The X-ray diffraction (XRD) and FTIR results provide the evidence that we can adjust the pore size by varying the Ti/Si ratio. However, there is a limit of Ti/Si ratio favoring the formation of specific structures; the ordered structures will be destructed at higher Ti/Si ratio. The scanning electron micrograph (SEM) and transmission electron micrograph (TEM) images reveal that the Ti-MCM-41 materials exhibit diverse morphologies, including ordered rods, threads and bundles, hexagonal flakes, tubes, discoid rings and helix tubes. We tentatively elucidate that the formation of the complex morphologies can be attributed to the crystal growth mechanism and the defect theory.     

Synthesis and characterization of V- and Ti-substituted mesoporous materials

Mesoporous Ti- and V-containing materials have been synthesized with different degree of loadings via incorporation of titanium (IV) isopropoxide and vanadium (V) oxide in the initial precursor gels. These mesoporous materials were compared with pure siliceous MCM-41 synthesized at the same conditions without adding metal precursors. The UV–vis and Raman measurements confirmed that the vanadium and titanium were mainly tetrahedrally coordinated and their coordination is not changing after calcinations. At high amount of Ti and V, the regular mesoporous long-range order decreases, however, the V- and Ti-mesoporous samples do not collapse upon calcinations.