载银二氧化钛纳米管表面pH敏感膜构建及其抑菌特性

采用表面涂覆硅烷偶联剂KH550、两步光接枝、阳极氧化等方法,在钛表面成功制备出一种pH型敏感膜覆盖的载银二氧化钛(TiO2)纳米管阵列。利用扫描电镜(SEM)、透射电镜(TEM)、能谱分析(EDS)、原子吸收光谱(AAS)对该pH敏感膜覆盖的载银TiO2纳米管阵列理化性能进行了表征,采用抑菌环实验定性考察了样品的抗菌特性,并计算其抑菌率。结果表明,含银离子溶液在毛细管力作用下大量进入TiO2纳米管中,并在pH型敏感膜的调控下,使银离子在不同pH环境下具备不同的释放行为,从而达到良好的控释效果;载银TiO2纳米管的抑菌率与银离子负载量成正比,且抗菌性能持久。     

载Ag二氧化钛纳米管的制备及其光催化性能

Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticles in 10 mol·L-1NaOHsolution at 110 ℃ for 24 h. The Ag loaded titania nanotubes (Ag/TNTs) were obtained by chemical deposition method with the TNTs suspending in the AgNO3 solution (pH=8) at 50 益. The characterizations of the as-synthesized samples were performed by TEM, EDS, XRD, XPS, and UV-Vis spectra. The photocatalytic performance of the Ag/TNTs was investigated by UV-light induced photocatalytic decomposition of methyl orange(MO). The results showed that the inner/outer diameters of TNTs were about 6/10 nm and the length was several hundred nanometers. Both the shape and the crystalline of the nanotubes were not changed after the modification. The zero oxidation state Ag quantumdots, about 4 nmin diameter, were well dispersed on the external surface of the nanotubes. Ag/TNTs exhibited enhanced absorption at the visible range in the UV-Vis spectra. The Ag nanoparticles were found to significantly enhance the photocatalytic activity of TiO2 nanotubes, and the catalyst system was demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both rutile-phase TiO2 nanoparticles and pure TNTs. After irradiation for 60 min, the decomposition rates of MO solution in rutile-phase TiO2 nanoparticles, TNTs, and Ag/TNTs systemwere 46.8%, 57.2%, and 92.2%, respectively.     

阳极氧化法制备二氧化钛纳米管及其在太阳能电池中的应用

介绍了阳极氧化法制备二氧化钛纳米管的技术发展历程, 论述了其制备过程及生长机理, 探讨了电解液、pH值、氧化电压、氧化时间、氧化温度和后处理方法等因素对TiO₂纳米管结构和形态的影响, 综述了近几年来利用TiO₂纳米管组装染料敏化、量子点和本体异质结等太阳能电池所取得的进展, 展望了其未来发展趋势和应用前景.     

二氧化钛纳米管/镍复合材料的可控制备及其微波电磁性能

二氧化钛纳米管可作为载体,经过磁性金属修饰,制备陶瓷基金属纳米复合材料.本文利用二氧化钛纳米管为载体,经过硅烷化改性,钯催化沉积金属镍,制备一种陶瓷基/镍纳米复合材料,并利用TEM,XRD,FTIR和XPS等方法表征该复合材料的结构特征.结果表明二氧化钛纳米管表面镍沉积均匀,镍晶粒度尺寸为9.7nm,具有衍射宽化特征.沉积镍后,纳米管端部呈开口特征,仍具有空腔结构.在外加电磁场作用下(8～12GHz),复合材料具有较高的磁导率和磁损耗,但具有很低的介电损耗.该复合材料具有长径比高、比重小、重量轻、镍含量少等特点.人们还可在二氧化钛纳米管外部沉积其他金属或合金(如铁、钴),调控复合材料的电磁性能,用于开发薄而轻的电磁活性复合材料.     

阳极氧化法制备二氧化钛纳米管及其在太阳能电池中的应用

介绍了阳极氧化法制备二氧化钛纳米管的技术发展历程, 论述了其制备过程及生长机理, 探讨了电解液、pH值、氧化电压、氧化时间、氧化温度和后处理方法等因素对TiO₂纳米管结构和形态的影响, 综述了近几年来利用TiO₂纳米管组装染料敏化、量子点和本体异质结等太阳能电池所取得的进展, 展望了其未来发展趋势和应用前景.     

镧掺杂二氧化钛纳米管光催化性能

以多孔有序阳极氧化铝为模板,利用溶胶-凝胶法制备掺杂La的二氧化钛纳米管,用场发射扫描电子显微镜、X射线衍射仪和比表面分析仪对其进行表征,以甲基橙为目标降解物,对比未掺杂的二氧化钛纳米粉、纳米管以及掺杂的二氧化钛纳米粉研究其光催化性能,并对降解机制进行分析。结果表明：适量的掺杂有利于提高二氧化钛纳米管的光催化性能,掺杂存在一个最佳量,本试验条件下为1%（质量分数）。掺杂的二氧化钛纳米管光催化性能优于掺杂的纳米粉。     

二氧化钛纳米管阵列的构建及其光电催化性能

利用阳极氧化法制备了TiO2纳米管阵列, 研究了其光电化学性能, 并且应用该电极对偶氮染料催化降解进行了初步研究.     

调节pH控制载银纳米TiO2表面包覆的PMMA

测定了十二烷基磺酸钠(SDS)在载银离子纳米TiO2颗粒表面的等温吸附曲线,在SDS达到临界胶束浓度(CMC)时,研究了pH=2.0(等电点以下)和pH=7.0(等电点以上)时甲基丙烯酸甲酯(MMA)在TiO2粒子表面的乳液聚合.采用改性前后TiO2的Zeta 电位的变化、红外光谱(FT-IR)及差热分析(DTA)等表征方法评价了改性效果.结果表明:PMMA成功包覆到TiO2表面,包覆率达17.8%,载银TiO2的表面由亲水变为亲油;在pH=2.0,cSDS=5.0 mmol/L时,Ag+的脱附量只有8%.     

一步水热合成铜纳米颗粒负载二氧化钛复合纳米管及其可见光催化活性

采用一步水热法合成了Cu纳米粒子负载二氧化钛纳米管材料. 利用透射电子显微镜(TEM)、X射线衍射仪(XRD)、能谱仪(EDS)等对材料的相组成、形貌以及形成过程进行了研究. 制得的Cu-TiO₂复合纳米材料长度约为100 nm, 直径10-15 nm, 其上负载的Cu纳米粒子尺寸约为5 nm. BET比表面积测试表明实验制备的Cu-TiO₂复合纳米管的比表面积为154.67 m²·g^-1. 通过调节水热反应时间和钛前驱体种类, 研究了该复合纳米管材料的形成机制. 结果表明: 非晶态的钛源对于成功一步合成Cu-TiO₂复合纳米管至关重要. 同时, 实验中观察到铜纳米粒子的尺寸随水热反应时间延长而减小(反奥氏陈化过程), 这一现象有助于纳米粒子的可控合成.紫外-可见吸收光谱表明该复合纳米管在350-800 nm范围内有较强的吸收, 并在550-600 nm范围观察到Cu的表面等离子激元吸收带. Cu-TiO₂界面处形成的肖特基势垒有助于加快光生载流子的输运, 提高光生电子-空穴对的分离效率. 光催化实验表明Cu-TiO₂复合纳米管在可见光下具有较高的催化活性.     

光析出二氧化钛负载银膜的制备及其光催化特性

以二氧化钛膜为载体,配制一定浓度的AgNO₃溶液,利用光析出方式在氧化钛膜表面还原析出Ag,控制光析出时间来控制氧化钛膜表面上的银析出量,制备银负载氧化钛膜,研究膜的抗菌特性和光催化特性.结果表明:由于银在氧化钛膜上的负载,使膜的抗菌性能得到很大的提高,在保持氧化钛膜的光催化能力基本维持不变的前提下,由于在氧化钛膜的表面负载银,对E.coli和青霉菌的杀菌能力分别提高了10⁴和10²,光催化降解甲基橙的能力与氧化钛膜相比,能够提高10%左右,显示了良好的光化学特性.     

阳极氧化法制备二氧化钛纳米管及其荧光性质

室温下采用电化学阳极氧化法在NaF、Na₂SO₄和H₂SO₄的混合溶液中用化学处理后的纯Ti片表面组装了一层结构高度有序的高密度TiO₂纳米管阵列。考察了几种主要的实验参数(阳极氧化电压、温度、电解液浓度)对TiO₂纳米管阵列形貌和尺寸的影响，探讨了二次阳极氧化对纳米管形貌的改善。对TiO₂纳米管阵列进行扫描电子显微镜(SEM)和荧光(PL)分析，探讨其生长机理。结果表明，孔径随阳极氧化电压的升高而变大，温度、电解液浓度影响反应过程中电流密度的大小；二次阳极氧化得到的纳米管的有序性有所改善，孔径大小更为均一，并且发现TiO₂纳米管的荧光具有量子效应。     

宽电压范围下阳极氧化制备TiO_2纳米管阵列及其热稳定性

采用电化学阳极氧化技术,以含有NH4F和H2O的甘油溶液为电解液,在宽氧化电压范围(20~100V)下于纯钛表面制备了结构高度有序的TiO2纳米管阵列。利用扫描电子显微镜(SEM)考察了阳极氧化工艺(氧化电压、NH4F浓度、环境温度、水分含量等因素)及退火处理对纳米管形貌的影响;采用X射线衍射分析(XRD)表征了不同氧化电压和退火前后TiO2纳米管阵列的物相;并从电流-时间曲线出发简要地分析了纳米管阵列的形成机理。结果表明,纳米管的内外径和管长随氧化电压的增大而增大;NH4F浓度和环境温度对纳米管形貌有一定的影响;水分含量的多寡决定了能否在高电压下自组装形成纳米管阵列;TiO2纳米管阵列具有良好的热稳定性,管状形貌可以保持到700℃;直接制备的TiO2纳米管阵列均为无定型结构,经450℃退火处理后,无定型的TiO2纳米管转变为锐钛矿相,而600℃退火处理后,部分锐钛矿相转变为金红石相。     

Photoelectron Properties and Organic Molecules Photodegradation Activity of Titania Nanotubes with CuxO Nanoparticles Heat Treated in Air and Argon

Titania is very famous photocatalyst for decomposition of organic pollutants. Its photocatalytic properties significantly depend on the morphology and chemical composition of the samples. Herein, the TiO₂ nanotubes/Cu_xO nanoheterostructures have been synthesized and the effect of heat treatment performed in molecular atmospheres of air and argon on their photoelectrochemical and photocatalytic properties has been studied. The prepared samples have a higher reaction rate constant compared to TiO₂ nanotubes in the decomposition reaction of methylene blue molecules. It is established that in argon treated nanoheterostructures, the copper oxide is present in two phases, CuO and Cu₂O, while in air treated ones there is only CuO. In the TiO₂ nanotubes/Cu_xO samples, Cu²⁺ ions and molecular O₂⁻ radicals were detected while in TiO₂ nanotubes only carbon dangling bond defects are present. The dynamics of O₂⁻ radicals under illumination are discussed. It was shown that the TiO₂ nanotubes do not exhibit photocatalytic activity under visible light. The mechanism of the photocatalytic reaction on the surface of the TiO₂ nanotubes/Cu_xO samples was proposed. It is assumed that a photocatalytic decomposition of organic molecules under visible light at the surface of the nanoheterostructures under investigation is realized mainly by the reaction of these molecules with photogenerated O₂⁻ radicals. The results obtained are completely original and indicate the high promise of the prepared photocatalysts.     

Ag/TiO2聚丙烯负载膜的制备及其光催化与抗菌特性研究

以聚丙烯负载二氧化钛膜为载体,在一定浓度的AgNO3水溶液中,利用光还原在氧化钛膜表面还原Ag,制备载银二氧化钛负载膜,在室光和太阳光下,分别选择Ag/TiO2聚丙烯膜、TiO2聚丙烯膜和活性炭聚丙烯膜,研究膜的抗菌特性和光催化特性.结果表明:Ag/TiO2负载膜由于同时具有Ag和TiO2的双重效用,显示了良好的杀菌特性,无论是在室内还是太阳光下,都没有检测到活的微生物;在水溶液中检测Ag/TiO2负载膜和TiO2负载膜的光催化特性,发现由于银离子的催化活性中心的作用,光催化降解甲基橙的能力与TiO2负载膜相比,能够提高10%左右,显示了良好的光化学特性.     

Fabrication and Characterization of LaF3/Titania Nanotube Array Electrode for Determination of Fluoride Using a Headspace Single-Drop Microextraction System

LaF₃/titania nanotube array (TNAs) electrodes were fabricated by electrodeposition of LaF₃ on synthesized TNAs. The electrode was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectrometer (EDS). The electrode exhibited excellent response to fluoride ion. The linear calibration range achieved four orders of magnitude of F^- concentration (10^?6–10^?2 mg/ml) and the sensitivity of the electrode is higher than that of ordinary fluoride ion selective electrodes (mode PF-1). The limit of detection (LOD) was estimated to be 4.39 × 10^?7 mg/ml (S/N = 3). The novel electrode was applied to the determination of trace fluoride ions in tap water and toothpaste. Finally, a headspace single-drop microextraction (SDME) system coupled with LaF₃/TNAs electrode was successfully applied to determine fluoride in milk samples. The results are satisfactory with an average relative standard deviation (RSD %) of 0.51% and recovery from 96.3% to 107.3%.     

TiN纳米管的制备及其作为SERS基底的应用

采用阳极氧化法在钛片表面制备TiO₂纳米管阵列,并经氨气氮化得到TiN纳米管阵列,通过XRD、SEM、XPS、UV-Vis对基底的组成、形貌和光学性能进行了表征,并以罗丹明6G（R6G）为探针分子,对TiN基底的SERS活性进行检测。结果显示,TiO₂纳米管经800℃以上高温可转化为TiN纳米管,纳米管直径在100~200 nm,排列规整有序。氮化后的样品在500~600 nm处出现TiN的等离子体共振吸收峰,该基底显示出较高的SERS活性,对R6G分子的检测极限可达~10^-7 mol·L^-1,增强因子达~10⁵。     

Theoretic and Experimental Studies on Titania Nanotube Doped with Ag Metal Ions

The electronic state density and energy bands of Ag-doped anatase TiO2 are studied by WIEN2k software package based on DFT. The calculation results show that the band-gap of anatase titania became bigger after doping with Ag metal ions. The band-gap transfers from 2.04 to 2.5 eV, but a new energy band appears among the forbidden band after the Ag atom substitution. The interband width of Ag-TiO2 is 0.17 eV, which is located at –0.07 eV; more excitation and jump routes are opened for the electrons. The lowest excitation energy can achieve 1.2 eV, which may allow the photons with lower energy (at longer wavelength, such as visible light) to be absorbed. Ag ions are implanted into the titania nanotube sample by MEVVA (Metal Vapor Vacuum Arc) implanter. The photo-electrochemical response and photo-degradation experiment of titania nanotube samples implanted with Ag ions are tested under UV and visible light; the results indicated that the performance of implanted titania naotubes is enhanced both under UV and visible light; it is worth mentioning that the photocurrent density can reach 0.145 mA/cm2 under visible light, which is 181 times higher than those of pure TiNT, and the k value of degradation methyl orange can obtain 0.30 h-1, which is 71 times higher than that of pure TiNT. All the experimental results are consistent well with the theoretic ones.     

Synthesis,Characterization, and Photocatalytic Properties of Ag/TiO2 Composite Nanofibers Prepared by Electrospinning

Ag nanoparticles (Ag NPs) embedded titanium dioxide (TiO₂) nanofibers were fabricated by colloidal sol process, electrospinning, and calcination technique. Calcination of the electrospun nanofibers were heat treated at 600°C for 180 minutes in air atmosphere. X-ray diffraction patterns exhibited that the anatase phase and silver coexisted in the resulted Ag NPs/TiO₂ nanofibers; transmission electron microscopy demonstrated Ag NPs well spread in the porous microstructure of composite fibers. The prepared nanofibers were utilized as photocatalyst for degradation of methyl orange. The degradation rate of methyl orange dye solution containing Ag/TiO₂ composite nanofibers is 99% only after irradiation for 3 hours. It is proposed that these new Ag NPs/TiO₂ composite nanofibers will have potential application in water pollution treatment.      

Effect of Incorporation of Silver on the Electrical Properties of Sol-Gel-Derived Titania Film

Metallic Ag nanoparticles-incorporating titania films were prepared using the sol-gel method. X-ray diffraction (XRD) patterns, UV/Vis optical spectra and transmission electron microscopy (TEM) images were recorded to characterize the Ag/titania composite films. Electrometer was used to estimate the resistance of Ag/titania composite film to understand the effect of the incorporation of metallic Ag nanoparticles on the electrical properties of titania film. The results showed that metallic Ag nanoparticles distributed randomly in titania film and most metallic Ag particles size was in the range of 5–15 nm. The agglomeration of a small quantity of metallic Ag particles occurred and when the amount of Ag species was increased the agglomeration was enhanced. The resistance of Ag/titania composite films decreased greatly compared with pure titania film.