二氧化钛纳米管制备及其光催化降解有机物应用研究进展

介绍了近年国内外二氧化钛纳米管的几种制备方法,有水热合成法、模板法和阳极氧化法,叙述了二氧化钛纳米管光催化氧化技术在有机污染物降解方面的研究进展。认为今后的研究和发展方向为:优化二氧化钛纳米管光催化反应光谱可利用的范围,提高二氧化钛纳米管的催化活性,探索二氧化钛纳米管光催化氧化降解有机污染物中的优化条件,加强专门针对降解有机污染物的二氧化钛纳米管的研究,进一步的研究反应机理,加强对二氧化钛纳米管在各个领域应用的探索,并转化为实际工程应用。     

二氧化钛纳米管的制备、改性及应用

二氧化钛纳米管因其特殊的形貌和高度有序的特性成为了目前研究的热点之一.本文系统回顾了近年来有关二氧化钛纳米管的相关研究,着重阐述了二氧化钛纳米管的制备方法,主要包括模板法、阳极氧化法、水热法;在此基础上,详细论述了掺杂、复合等对二氧化钛纳米管进行改性的方法;并简要介绍了二氧化钛纳米管及其复合材料在环境、能源等领域的应用.最后,展望了二氧化钛纳米管的主要研究方向是对形成机理、管形貌调控、表面改性等方面做进一步研究,以期为后续的研究提供参考.     

水热法制备CuS二氧化钛纳米管复合电极及光催化有机磷

采用阳极氧化和水热法制备CuS二氧化钛纳米管复合电极,采用扫描电子显微镜(SEM),X射线衍射(XRD)等方法进行表征.结果表明,该方法成功制备了CuS二氧化钛纳米管复合电极.研究了复合电极对磷系阻垢剂的光电催化性能,同时详细研究了掺杂物浓度(CuCl2、Na2S2O3)、水热时间、降解电压对CuS二氧化钛纳米管复合电极的影响.研究结果表明:半导体耦合掺杂的二氧化钛纳米管的的光电化学性质,优于纯的二氧化钛.     

NH4F/H2SO4电解液中TiO2纳米管的制备及形成机理

采用阳极氧化法,在NH4F/H2SO4电解液体系中制备了大面积的有序二氧化钛纳米管阵列。通过扫描电镜和X射线衍射分别对二氧化钛纳米管的微观形貌及相结构进行表征,并探讨了氧化电压对纳米管形貌的影响及纳米管的形成机理。结果表明,在NH4F/H2SO4电解液中,氧化电压为15~20 V时可制备出有序的二氧化钛纳米管,管径随电压增加而增大。     

二氧化钛纳米管阵列制备及其在染料敏化太阳能电池中的应用

以NH4F的乙二醇溶液为电解液,采用阳极氧化法在钛板上制备二氧化钛纳米管阵列,通过调控氧化电压改变纳米管的长度和管径,得到了长度为10～45μm、管径为50～150nm的二氧化钛纳米管.分析了阳极氧化实验条件对TiO2纳米管尺寸的影响,并研究了TiO2纳米管阵列的尺寸对染料敏化太阳能电池(dye-sensitized ...     

石墨烯-二氧化钛纳米管催化剂的光解水制氢性能研究

为改善能源短缺,对新型光催化水解制氢材料进行了研究。通过改进Hummer法制备氧化石墨,溶胶-凝胶法制备锐钛矿型二氧化钛,采用浓碱法制得石墨烯-二氧化钛纳米管催化剂,考察了不同石墨烯的掺杂量对催化活性的影响。经过光解水制氢实验发现,掺杂不同质量分数石墨烯的催化剂催化活性得到了进一步提高,其中掺杂量为1%的产氢活性最好,产氢速率是纯二氧化钛纳米管的2. 5倍。通过BET、XRD、UV以及FT-IR等方法对催化剂进行了表征。结果表明,石墨烯与二氧化钛纳米管成功复合,并且石墨烯的掺杂在一定程度上提高了催化剂的BET比表面积;催化剂对可见光的响应范围得到进一步扩大,这为催化剂光解水制氢性能的提高提供了有力的条件。     

纳米二氧化钛管阵列的制备及其光催化氧化降解甲基橙性能的研究

本文采用电化学阳极氧化法制备了管径为90—150nm的纳米管阵列。采用SEM和XRD对制备的二氧化钛纳米管阵列进行了表征。考察了焙烧温度对阳极氧化法制备纳米二氧化钛管阵列晶形结构的影响。将所制备的纳米管用于光催化降解甲基橙反应,考察了其在通气和不通气条件下光催化降解甲基橙的性能。结果显示：在550℃下焙烧的纳米管阵列具有良好的催化活性;反应器中通氧气可以提高纳米二氧化钛对甲基橙的光催化活性。     

Ti/TiO_2/Pd纳米电极的制备和电催化性能

采用阳极氧化法在纯钛表面生成结构高度有序的二氧化钛纳米管阵列,并通过室温固相反应制备了钯纳米颗粒。采用自组装方法将钯纳米颗粒修饰到Ti/TiO2表面制备了Ti/TiO2/Pd纳米电极。利用电子扫描显微镜、X-射线衍射分析二氧化钛纳米管、钯纳米颗粒和纳米电极的微观结构和表面形貌,并研究了Ti/TiO2/Pd纳米电极对甲醇的电催化性能。结果表明,TiO2纳米管排列整齐有序,Ti/TiO2/Pd电极中Pd纳米颗粒均匀分散在TiO2纳米管表面。电化学测试结果表明,Ti/TiO2/Pd纳米电极对甲醇的电催化氧化过程具有很好的电催化活性。     

TiO2纳米管阵列的制备、改性及应用研究

二氧化钛因其化学性质稳定,无毒,无污染,是环境友好型材料.它的一维纳米材料尤其是二氧化钛纳米管在绿色能源太阳能和环境治理方面有很大的潜在应用价值,激起了全球科学家的兴趣.基于前人对二氧化钛纳米管的研究成果,我们总结了目前的制备方法、改性及其应用方面的研究现状,以期对二氧化钛纳米管的未来研究提供一些知识基础的支持.     

晶种法制备3D-TNAs@NH2-MIL-125复合电极及其光电催化性能研究

以钛丝网为基底制备三维二氧化钛纳米管阵列电极(3D-TNAs),之后通过晶种滴加法将NH₂-MIL-125与三维二氧化钛纳米管阵列复合,制备3D-TNAs@NH₂-MIL-125复合电极材料。通过调节晶种时间,研究不同制备时间对复合电极表面形貌、物理化学性质及光电化学性能的影响。结果表明,通过晶种滴加法合成的3D-TNAs@NH₂-MIL-125复合电极具有优异的光电化学性能,其中晶种时间为6 h的复合电极综合性能最好,在模拟太阳光及0.7 V外加偏压的条件下,反应时间为150 min时对亚甲基蓝的降解率可达97.8%。     

TiO2纳米管阵列的研究进展

近年来TiO2纳米管阵列在光催化等领域展现出良好的应用前景,对其制备技术和应用研究已成为研究的热点。本文对TiO2纳米管阵列的制备方法作了综合介绍,概述了其研究现状及最新应用进展。     

Preparation and Photocatalytic Properties of PEG-Silicone Polyesters/Titanium Dioxide Nanotube Composites

This study uses a series of hydrophilic PEG-silicone polyester and titanium dioxide nanotubes to prepare high-performance titanium dioxide nanotube (TNT) composites. The decomposition of these titanium dioxide nanotube composites for the methylene blue is investigated by using UV-Vis spectroscopy. These changes in structure have been observed by FTIR and Raman analysis at 365 nm UV irradiation. The surface microstructures of composites were characterized with scanning electron microscopy (SEM). It was found that titanium dioxide nanotube composites possessed excellent solubility and dispersion effects. This makes fixation of photocatalysts possible and retards oxidation of organic materials in the PEG-silicone polyesters.     

The correlation between the interference colour and growth procedure of anodic titanium dioxide nanotube arrays

Titanium dioxide nanotube arrays were anodised from titanium foils in an aqueous electrolyte solution of hydrofluoric acid. The formed oxide showed visually different colours owing to light interference in the titanium dioxide layer. The behaviour of interference colour in anodic titanium dioxide film was investigated by varying anodisation parameters such as the applied voltage and the anodisation time. The morphologies and the crystalline phases of anodised samples were studied on a field emission scanning electron microscope and X‐ray diffractometer. The correlation between the interference colour and growth procedure of anodic titanium dioxide nanotube arrays was studied. The anodic films prepared under different conditions consisted of a compact oxide film with a nanoporous/tubular structure upon/beneath it. The crystalline phase of the anodic oxide layer was amorphous. The optical properties of the oxide film were investigated on a spectrophotometer. Optical interference could be detected in compact oxide layers when the thickness of the titanium dioxide was as small as 70 nm. In general, the interferences of the nanoporous/tubular structures were lower than those for compact structures. The empirical colour properties were estimated by the L*a*b* system. The relationships between the interference colour of anodic titanium dioxide film and its thickness and morphology are discussed.     

Photocatalytic Degradation of Reactive Black-5 Dye with Novel Graphene-Titanium Nanotube Composite

Graphene-titanium nanotube composites with different ratios of graphite oxide were prepared via the hydrothermal method using ascorbic acid as a reducing agent. Properties of materials were characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy, high resolution transmission electron microscopy and UV–vis diffuse reflectance spectroscopy. The average diameter of the titanium dioxide nanotubes was about 8 nm. The photoresponse of nanocomposites have been extended to visible-light regions. In addition, graphene-titanium nanotube composites showed higher photocatalytic degradation efficiency for reactive black 5 (RBK5) than pure titanium dioxide and the 15%graphene-titanium nanotube composites catalysts possessed the best photocatalytic activity. The degradation efficiency for RBK5 dyes increased with increased dosage of graphite oxide from 3%-15% and decreased with increasing initial RBK5 concentration. This paper not only reports the fabrication of highly active photocatalysts but also provides insight into the photocatalytic mechanism of graphene-titanium nanotube composites.     

碳基材料复合半导体光催化剂的制备及应用研究进展

半导体光催化剂被广泛地应用于光催化领域,但其常因自身的禁带宽度较大、量子效率较低、催化效率较低、与反应物接触几率较低等因素在实际应用中受到诸多限制。而碳基材料作为一类结构稳定的新材料,具有稳定性强、导电能力强、比表面积大、包含大量的吸附位点等特性,与光催化剂复合之后,能够有效减小其禁带宽度、降低其载流子的复合率并为其提供更多的吸附位点,很大程度上提高了光催化剂的光催化性能。该文章以石墨烯、碳纳米管、富勒烯以及碳纤维等碳材料与各类半导体光催化剂复合为例,综述了碳基材料与光催化剂复合的工艺、提高其光催化性能的机理、影响碳基材料改性程度的因素及其在产氢、杀菌等方面的应用,并且对其进行了展望。     

Nb doped TiO2 nanotubes for enhanced photoelectrochemical water-splitting

Nanostructured titanium dioxide is one of the classic materials for photoelectrochemical water splitting. In the present work we dope TiO(2) nanotube anodes. For this, various low concentration bulk-Nb-doped TiO(2) nanotube layers were grown by self-organizing anodization of Ti-Nb alloys. At Nb-contents around 0.1 at%, and after an adequate heat-treatment, a strongly increased and stable photoelectrochemical water-splitting rate is obtained.     

模板法合成TiO2纳米阵列及其微观结构表征

采用异丙醇钛[(C4H9O)4Ti]为先驱体配制二氧化钛溶胶,以阳极氧化铝模板(AAO,孔径尺寸200 nm,厚度约60 mm)直接浸渍和负压辅助浸渍的方法制备二氧化钛纳米管或管棒混杂的阵列结构,所得产物在450℃下进行热处理后,化学刻蚀去除模板. 利用FE-SEM, HR-TEM以及XRD对其微观形貌、结构等进行了观测和分析. 结果表明,产物450℃热处理后为多晶锐钛矿相. 模板法简单易行,制备出的管棒外径取决于模板孔道的尺寸,在负压辅助下可有效提高产物的连续性.     

基于自润湿溶液的纳米表面传热性能

采用阳极氧化法在钛板表面制备出TiO₂纳米管阵列,并以其为加热表面。以含不同浓度丁醇的自润湿溶液为实验工质,考察了自润湿溶液浓度变化对系统临界热流密度和传热系数的影响,并从气泡行为的不同分析了两者耦合强化传热的机理。结果表明：相比于光滑表面和蒸馏水的常规组合,TiO₂纳米管表面和自润湿溶液耦合传热使得系统的临界热流密度大幅度提高,随自润湿溶液浓度的升高,传热系数依次降低。具有超亲水性和较大粗糙度的纳米管表面与1%（质量分数,下同）自润湿性溶液相耦合时,其最大传热系数和临界热流密度分别为11.963 kW·m^-2·℃^-1与623.706 kW·m^-2,比常规组合传热分别提高了84.1%和143.8%。由气泡可视化可知,耦合传热在沸腾过程中产生的气泡细小,脱离速度快,不易团聚,合并后的气泡易破碎,易形成微气泡,从而使系统进入剧烈的微气泡沸腾状态。气泡的高脱离频率和特殊有效的液体补充路径,是提高系统传热系数和临界热流密度的主要原因。     

A convenient, general synthesis of carbide nanofibres via templated reactions on carbon nanotubes in molten salt media

Carbide nanofibres were synthesized by reaction of various transition metals with carbon nanotubes using a molten LiCl-KCl-KF salt system as a reaction medium. Metal sources included titanium, zirconium, hafnium, vanadium, niobium and tantalum powders. Multi-walled carbon nanotubes were used both as a carbon source and also as a template for the preparation of titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide and tantalum carbide nanofibres. Generally, the carbide products were characterized by scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and electron energy loss spectroscopy. The polycrystalline carbide nanofibres produced in these reactions have a similar morphology to that of their multi-walled carbon nanotube precursors. However, when using titanium mixed with titanium dioxide as a titanium source, both polycrystalline and straight, single crystal titanium carbide nanofibres are formed.     

新型酸溶性富钛料在硫酸法钛白粉生产中的应用

介绍了当前硫酸法钛白粉生产现状以及中钛科技研发的新型酸溶性富钛料产品、特性、生产工艺及在硫酸法钛白粉生产中的应用。通过工业试验对比可知,采用新型酸溶性富钛料为原料生产的钛白粉,根据添加比例不同,可以不同程度降低矿(渣)耗、酸耗和能源消耗。