中空TiO2微球的可控制备及在隔热涂料中的应用

为满足隔热涂料拥有高近红外反射率的同时还具备较低的导热性能的需求,研发了一种优秀的隔热填料：中空TiO₂微球。中空TiO₂微球空腔结构可储存大量空气,使得导热系数较低,同时壳层结构对红外线具有较强反射能力,是理想材料之一。以自制粒径约340 nm单分散Si O₂微球为硬模板,采用牺牲模板法在最优条件下成功制备粒径约510 nm,壳厚120 nm,空腔尺寸260 nm左右,分散较均匀的中空TiO₂微球。探究氨水浓度、反应时间对Si O₂微球粒径影响,得出适宜反应时间为2 h,且氨水浓度在一定范围内增大,Si O₂粒径随之增大。研究了水热时间、温度、蚀刻液种类对中空TiO₂微球形貌的影响,其中50～60℃Na OH溶液蚀刻1 h最适宜。测试了中空TiO₂微球在300～2 500 nm的反射率,400～1 350 nm内反射率维持在90%。用中空TiO₂微球制备隔热涂料,隔热性能比用钛白粉、空心玻...     

制备方法对Co-Pd/TiO2催化剂催化CH4-CO2梯阶转化的影响

以钴、钯为活性金属, 分别采用浸渍法和溶胶-凝胶法制备了Co-Pd/TiO₂催化剂, 考察了不同制备方法制备的Co-Pd/TiO₂催化剂对CH₄-CO₂梯阶转化直接合成C₂含氧化合物的影响。利用XRD、XPS和N₂-吸附-脱附对催化剂进行了表征。结果表明:两种方法制备的催化剂反应前与反应后表面织构都存在较大变化, 且催化剂中均存在CoTiO₃物种, 这是活性金属Co与载体TiO₂之间发生强相互作用, CO²⁺替代TiO₂晶格中的Ti⁴⁺的结果;CoO和金属Pd可能是该反应的活性中心;反应前与反应后溶胶-凝胶法制备的催化剂的表面Co含量均低于浸渍法制备的催化剂, 而表面Pd含量则均高于浸渍法制备的催化剂, 且溶胶-凝胶法制备的催化剂各种产物的生成速率均高于浸渍法制备的催化剂, 因此, 与浸渍法制备的催化剂相比, 溶胶-凝胶法制备的催化剂具有更好的催化活性。     

溶胶—凝胶法制备TiO2薄膜的工艺研究

以钛酸四丁酯为原料，乙醇为溶剂，采用溶胶—凝胶法制备TiO₂薄膜，利用旋转粘度计、光学显微镜和扫描电子显微镜研究了浓度、加水量、TiO₂溶胶黏度、水解抑制剂种类及用量对镀膜效果的影响。在此基础上，采用浸渍—提拉法经过三次镀膜在载玻片上成功制备出均匀、致密的TiO₂薄膜。     

载体制备方法对Ni/TiO2催化剂顺酐液相加氢性能的影响

为了制备高活性和高选择性催化剂,实现顺酐下游加氢衍生物的定向合成,分别采用水热法、沉淀法和溶胶-凝胶法制备TiO2载体,并以浸渍法制备Ni质量分数为10%的Ni/TiO₂催化剂。采用N₂低温物理吸附、XRD、H₂-TPR及H₂-TPD等方法对催化剂进行表征,并评价催化剂的顺酐液相加氢性能。结果表明,以溶胶-凝胶法制备TiO₂为载体的催化剂具有最高的CC及CO加氢活性,在反应温度240 ℃和氢压5 MPa条件下,顺酐转化率为100%,γ-丁内酯选择性为52.2%,是相同反应条件下水热法TiO₂负载Ni催化剂的3.3倍和沉淀法TiO₂负载Ni催化剂的6.2倍。产生这一现象的原因与溶胶-凝胶法制备的TiO₂以锐钛矿和金红石混合晶相存在有关。     

磁性光催化剂Fe3O4/SiO2/TiO2的制备及光催化降解苯酚

采用撞击流-旋转填料床辅助沉淀法连续制备Fe₃O₄磁性纳米颗粒,然后采用溶胶-凝胶法制备了具有磁性核壳结构Fe₃O₄/SiO₂/TiO₂颗粒,通过傅里叶变换红外光谱（FTIR）、X射线衍射仪（XRD）、透射电子显微镜（TEM）、热重分析仪（TGA）、振动样品磁强计（VSM）和紫外-可见漫反射光谱（UV-vis）等对材料的微观结构、形貌及性能进行了表征。考察了正硅酸乙酯添加量、铁钛比对Fe₃O₄/SiO₂/TiO₂磁性催化剂催化性能的影响。结果表明：制得的Fe₃O₄/SiO₂/TiO₂结晶度好,磁响应性高。当正硅酸乙酯添加量为20mL、铁钛比为1∶8时,制备的Fe₃O₄/SiO₂/TiO₂纳米光催化剂表现出较高的光催化活性和磁性能,紫外光照射2h后,苯酚水溶液降解效率高达86.7%。     

一维TiO2-Al2O3载体的制备及其在加氢脱氮中的应用

为提高现有负载型NiMoS催化剂的加氢活性,以碳纳米管为结构导向剂,分别采用浸渍法和溶胶-凝胶法制备了2种一维TiO₂-Al₂O₃载体,并采用共浸渍法制备了相应的负载型NiMoS催化剂,探究了不同结构的载体对NiMoS/TiO₂-Al₂O₃催化剂加氢脱氮性能的影响。结果表明,当选择以溶胶-凝胶法制备的一维TiO₂-Al₂O₃为载体时,NiMoS/TiO₂-Al₂O₃催化剂上的加氢脱氮活性较高,在350℃、氢压为3 MPa、转速为400 r/min的条件下反应4 h,喹啉的转化率达到99%以上,脱氮率达到40.75%。     

用于环境净化的TiO2/AC复合材料的制备及其改性研究进展

二氧化钛（TiO₂）在光照下可以产生具有强氧化性能的活性基团,活性炭（AC）具有良好的吸附性能。将TiO₂负载在AC上制备的TiO₂/AC复合材料可以有效去除大部分难降解的有机污染物,因此在环境净化领域具有良好的应用前景。本文综述了TiO₂/AC复合材料的研究现状,介绍了目前TiO₂/AC复合材料的三种主要制备工艺：溶胶-凝胶法、溶剂热法和微波合成法。其中溶胶-凝胶法所制备的材料稳定性好、溶剂热法制备条件温和、微波合成法制备周期短。针对TiO₂/AC复合材料可见光吸收率低和量子利用率低等问题,介绍了离子掺杂、半导体复合、贵金属沉积等现有的TiO₂/AC复合材料改性方法。之后,概述了所制备的TiO₂/AC复合材料在去除难降解有机污染物（染料废水、药物类、酚类、挥发性有机物）中的应用。最后展望了TiO₂/AC复合材料在改性研究与实际应用过程中存在的挑战性问题及可行的解决方法,为TiO₂/AC复合材料深入研究和大规模工业生产应用提供参考。     

二氧化钛纳米管稳定Pickering乳液制备PS/TiO2纳米管复合微球

利用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH-570）,对水热法制备的TiO₂纳米管进行了表面改性,并用改性的纳米管为稳定剂,采用Pickering乳液聚合法制备了聚苯乙烯/TiO₂纳米管复合微球。采用红外光谱（IR）、光学显微镜、高分辨透射电镜（HRTEM）、高分辨扫描电子显微镜（FESEM）、X射线光电子能谱（XPS）等分析手段,对改性前后TiO₂纳米管以及复合微球的结构和形貌进行了表征,用三相接触角仪测试并优化了TiO₂纳米管的表面润湿性。研究结果表明,当m_KH-570/m_TiO2=15%时,改性TiO₂纳米管表面润湿性最佳,能很好地稳定Pickering乳液聚合,聚合后可以得到壳层为致密均匀TiO₂纳米管,核为聚苯乙烯的复合微球。     

介孔-大孔HPW/TiO2催化剂的制备及其催化氧化脱硫性能的研究

为了有效降低SO_x在环境中的排放,以嵌段共聚物F127和新合成的PMMA微球为双模板,采用溶胶-凝胶法制备了三维有序介孔-大孔x-HPW/TiO₂催化剂。利用扫描电镜、透射电镜、氮气吸附-脱附、X射线衍射和红外光谱研究了其结构,并考察了其催化氧化燃油中有机硫的性能。结果表明,x-HPW/TiO₂催化剂中存在高度有序的介孔-大孔结构,Keggin结构的HPW均匀分散在TiO₂孔道骨架中。该催化剂在常压、60℃下可使燃油中的二苯并噻吩（DBT）催化氧化完全,循环使用6次后对DBT的去除率仍可达到96%。     

非水解溶胶-凝胶法制备TiO2光催化薄膜

以TiCl4为前驱体,无水乙醇为氧供体,聚乙二醇(polyethylene glycol,PEG)为成膜控制剂,通过非水解溶胶-凝胶法制备了TiO2光催化薄膜.应用X射线衍射和热重-差式扫描量热研究了TiO2凝胶在热处理过程中的物相变化.采用场发射扫描电镜和光照甲基橙的降解实验研究了TiCl4浓度和镀膜次数对TiO2薄膜显微结构和光催化活性的影响.结果表明:非水解溶胶-凝胶法制备的TiO2薄膜开始出现金红石相的温度为750 ℃,高于传统水解溶胶-凝胶法制备的薄膜.TiCl4浓度和PEG用量是影响薄膜结构和光催化性能的关键因素.当TiCl4浓度为0.83 mol/L,PEG与TiCl4摩尔比为0.1时,所制备的薄膜是一种晶粒细小且孔隙及孔径分布均匀的多孔膜,这有利于提高薄膜的比表面积,薄膜具有最佳的光催化性能.     

Zirconia and titania composite membranes for liquid phase separation: preparation and characterization

Crack-free tubular TiO₂/ZrO₂ composite ceramic membranes on ZrO₂ supports have been successfully synthesized from colloidal titania sols by the sol-gel technique. The pore sizes of the prepared membrane were mainly controlled by the sol properties and the calcination conditions. The influence of different parameters such as additives and solvents on the hydrolysis and polycondensation properties of the sols was studied by DTA–TG and viscosity measurements. The TiO₂/ZrO₂ composite ceramic membranes were characterized by X-ray diffraction and scanning electron microscopy. Composite membrane permeability and rejection properties were also investigated. The results proved that the range of composite membrane flux and retention could be controlled by controlling the amount of polyethylene glycol (PEG). PEG in titania sol systems was suitable for use as an organic additive to fabricate crack-free composite membranes. The larger the amount of PEG added to the precursor solution, the larger the size and number of pores produced in the prepared membranes when the PEG was completely combusted during heat-treatment. By controlling the amount of PEG added to the precursor solution, TiO₂/ZrO₂ composite ceramic membranes with different pore sizes were prepared, which can be used in photocatalytic membrane reactors and applied in liquid–liquid or liquid–solid separation in future research.     

AUGMENTATION OF PHOTOCATALYTIC ACTIVITY OF TiO2 THIN FILMS PREPARED BY A SOL-GEL TECHNIQUE

In order to increase the photocatalytic activity on TiO₂ thin film per its external surface area, the structure of flat thin film was modified by adding a small amount of polyethylene glycol (PEG) to TiO₂ sol solution. By firing PEG contained in a TiO₂ gel film, a porous structure was developed. The photocatalytic activities of the thin films prepared thus were evaluated by the degradation of 2-propanol in the aqueous solutions under black light illumination. The photocatalytic activity of TiO₂ thin film prepared with added PEG 400 by 2.6 wt% or PEG 2000 by 9.5 wt% was increased by about 30% as compared to that prepared without added PEG.     

Photodegradation of phenol in water using silica-supported titania catalysts

Titania-coated silica microspheres containing 0.5–3.0 theoretical layers of TiO₂ have been prepared by homogeneous precipitation of TiCl₃. All these χ TiO₂-SiO₂ materials were characterized by X-ray diffraction and FT-Raman spectroscopy. TiO₂ species are distributed on the surface as small anatase crystals and possess a titania-like behavior with a performance equivalent to that of bulk TiO₂ for the photodegradation of phenol. The fraction of used titania is higher than that on bulk catalysts and the absorption of the irradiation by excess titania is prevented. The crystal size of titania particles is critical for optimum performance of the catalyst, since it determines the appropriate surface exposure of titanium sites. A minimum size appears to be required to efficiently mineralize phenol.     

Hydrothermal synthesis of titanium dioxides from peroxotitanate solution using different amine group-containing organics and their photocatalytic activity

Nanosized TiO₂ particles were prepared by hydrothermal method of the amorphous powders which were precipitated in an aqueous peroxotitanate solution using different amine group-containing organics. The physical properties of prepared nanosized TiO₂ particles were investigated. We also examined the activity of TiO₂ particles as a photocatalyst for the decomposition of orange II. The TiO₂ particles calcined at 400 °C were shown to have a stable anatase phase which has no organic compounds. The particles size of titania particles decreased from 15 to 10 nm as the carbon chain length increased. The titania nanoparticles were shown to have a polygonal shape prepared using NH₄OH and tetramethylammonium hydroxide (TMAOH) as additives, however, the micrographs showed the spherical and narrow size distribution prepared using tetraethyl-ammonium hydroxide (TEAOH) and tetrabutylammonium hydroxide (TBAOH). The titania particles prepared using TEAOH as an amine group-containing organic showed the highest activity on the photocatalytic decomposition of orange II. In addition, the titania particles calcined at 500 °C showed the highest activity on the photocatalytic decomposition of orange II.     

Photocatalytic oxidation of nitrogen oxide over titania–zeolite composite catalyst to remove nitrogen oxides in the atmosphere

The photooxidation of NO with oxygen over Hycom TiO₂ and zeolite (A and Y form zeolite: TiO₂-AZ and TiO₂-YZ) composite catalysts was studied to remove NO_x in the atmosphere. The photocatalytic oxidation activity of the titania in the composite catalyst in a proportion of AZ:TiO₂=3:7 is about three times larger than that in the bare titania. The adsorption behaviors of NO and NO₂ for the bare titania sample obey Langmuir adsorption equations of NO and NO₂, respectively. In the titania–zeolite composite catalysts, the adsorption data indicate the increase in the amount of NO adsorption on the TiO₂ phase and the decrease in the amount of NO₂ adsorption, compared with the bare titania. The acceleration of NO photooxidation rate, resulting from the increase in the amount of NO adsorbed and the decrease in the amount of NO₂ adsorbed, thus occurs on the TiO₂ phase. IR spectra, when irradiating the catalysts with UV, showed the immediate formation of nitrate and NO₂ species on the catalyst. The results lead to the conclusion that the zeolites promote the photocatalytic oxidation of NO over the titania.     

釉面分相对无铅CuO-MnO2系金属光泽釉的影响

以钙系生料釉为基础,引入结晶剂CuO、MnO₂制备无铅CuO-MnO₂系金属光泽釉;结合XRD、SEM-EDS进行物相组成定性分析和显微结构表征,系统探究外加TiO₂、V₂O₅以及玻璃粉对金属光泽釉釉面分相的影响。研究表明:一定量的TiO₂、V₂O₅引入能有效促进釉面的分相,将玻璃粉部分替换基础釉中的钾长石能使得釉熔体的高温粘度降低,并进一步加剧釉面分相,促进CuMn₂O₄铜锰尖晶石在釉层表面的析出和富集;当TiO₂引入量为2%,V₂O₅引入量为1%,玻璃粉引入量为25%(同为质量分数)时,金属光泽釉釉面效果最佳。     

Photoactivity of anatase–rutile TiO2 nanocrystalline mixtures obtained by heat treatment of homogeneously precipitated anatase

Nanosized titanium dioxide photocatalysts with varying amount of anatase and rutile phases have been synthesized. Homogeneous precipitation of aqueous solutions containing TiOSO₄ with urea was used to prepare porous spherical clusters of anatase TiO_2. Photoactive titania powders with variable amount of anatase and rutile phases were prepared by heating of pure anatase in the temperatutre range 800–1150 °C. The structure evolution during heating of the starting anatase powders was studied by XRD analysis in overall temperature range of phase transformation. The morphology and microstucture characteristics were also obtained by HRTEM, BET and BJH. The spherical particle morphology of TiO₂ mixtures determined by SEM was stable in air up to 900 °C. The photocatalytic activity of the sample titania TIT85/825 heated to 825 °C in air, contained 77.4% anatase and 22.6% rutile was higher than that nanocrystalline anatase powder. Titania sample TIT85/825 reveals the highest catalytic activity during the photocatalyzed degradation of 4-chlorophenol in aqueous suspension.     

Al2O3@TiO2复合生物载体的制备及其BSA吸附特性

通过钛酸盐和氧化钛溶胶两种制备途径在氧化铝（Al₂O₃）支撑体外包覆介孔氧化钛（TiO₂）层,分析了这两种途径制备的氧化钛表面结构与性质的差异及其对于BSA蛋白吸附性能的影响。以粒径分别为0.37、10.4和21.8 mm的三种氧化铝支撑体作为基材,用XRD、Raman分析了两种路径制备的氧化钛晶型均为锐钛矿相;N₂吸脱附分析其比表面积均在（100±10）m²·g^-1,两者具有相似的介孔结构。FESEM分析发现钛酸钾溶胶制备的氧化钛的形貌受到支撑体孔径的影响。对于在牛血清蛋白（BSA）吸附实验中,钛酸钾溶胶法包覆的20 mm粒径复合载体（SP20@K-TiO₂）吸附量为22.18 mg·g^-1,高于相同条件下氧化钛溶胶制备的Al₂O₃@TiO₂复合载体。SP20@K-TiO₂ 中TiO₂吸附量为150.88 mg·g^-1,相比于TiO₂粉体,复合载体中TiO₂对BSA蛋白吸附的性能得到提升。     

铁掺杂二氧化钛空心球的制备及性能

以TiF₄为钛源、九水合硝酸铁为掺杂前体,采用水热法制备铁掺杂的TiO₂空心微球。采用SEM、TEM、XRD、BET、XPS等技术对样品的形貌、结构、晶型、比表面积、元素组成等进行表征,以亚甲基蓝（MB）的光催化降解为目标反应,评价其光催化活性。结果表明,160℃下水热反应生成的纳米TiO₂空心微球晶型为锐钛矿,少量掺铁并不影响微球的形貌及晶体结构。光催化实验表明,160℃下水热反应12 h生成的TiO₂空心微球样品均匀性好、光催化活性最佳;铁掺杂能显著提高TiO₂空心微球的催化活性,当铁钛比为1.5:100时,所得样品粒径最小,比表面积最大,光催化活性最高。     

纳米二氧化钛环境风险模拟研究的溶胶配制方法

为了优化用于环境风险模拟研究的纳米二氧化钛颗粒溶胶的制备方法,研究了超声时间、分散剂、静置时间对商购纳米二氧化钛分散效果的影响,从而确定出分散体系稳定、粒径小且二氧化钛浓度较高的纳米溶液,以促进工程纳米材料环境风险的研究。结果表明,在100 mL超纯水中先加入六偏磷酸钠（SHMP）500 mg作分散剂,再加入100 mg商购纳米二氧化钛,然后超声15 min,并静置6 d,最终可得到平均粒径为（196±20） nm,TEM表征粒径为50~80 nm,Zeta电位为（-51.3±6.7） mV,实测分散质量浓度为（61.89±5.41） mg/L的颗粒溶胶。该方法可获得较高浓度、稳定的纳米二氧化钛颗粒溶胶,可为工程纳米材料环境风险模拟研究奠定良好的基础。