SnO2TiO2 复合半导体纳米薄膜的研究进展*

本文概述了SnO₂TiO₂ 复合半导体纳米薄膜的发展历史和研究现状,对比分析了“混合”、“核壳”和“叠层”3 种复合薄膜的结构和性能特点,着重论述了叠层结构的SnO₂ /TiO₂复合薄膜的光电化学和光催化特性。结合作者的研究工作,探讨了SnO₂ /TiO₂双层复合薄膜上下层厚度对其光催化活性的影响,指出复合薄膜光催化活性的提高可归因于电子从TiO₂ 向SnO₂ 的迁移。最后对SnO₂ /TiO₂复合薄膜的局限性和发展潜势做一简要分析,强调了该复合薄膜本身的应用特点。     

新型CdS/TiO2纳米复合材料的制备及其可见光催化性能研究

采用浸渍法和水热法相结合制备了新型的CdS/TiO₂纳米复合材料,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、UV-Vis吸收光谱(UV-VIS)、电子自旋共振谱(ESR)等对样品进行了表征,XRD、TEM表明所制备的新型CdS/TiO₂粒径小、分散均匀,TiO₂以锐钛矿型存在,CdS以高分散的立方相和六方相存在,对比直接法制备的CdS/TiO₂,新型的CdS/TiO₂对活性艳红X-3B具有明显提高的可见光催化活性;大量的束缚单电子氧空位及电子之间强相互作用是新型CdS/TiO₂可见光催化活性提高的主要原因.     

掺杂Mo6+对纳米TiO2薄膜亲水性的影响

用溶胶 凝胶法制备了一系列掺杂钼量不同的TiO₂纳米薄膜.用XRD,SEM和CAS(ContactAngleSystem)对TiO₂薄膜的结构和性能进行了表征.结果表明,Mo⁶⁺掺杂浓度对薄膜的热致亲水性和光致亲水性均有影响,当掺Mo⁶⁺质量分数为0.75%,热处理温度为400℃时,掺钼TiO₂薄膜在黑暗中放置72h后仍能表现超亲水性.     

阳极氧化TiO2纳米管阵列的制备与掺杂*

近年来,TiO₂纳米管阵列的制备与应用得到了广泛的研究。阳极氧化法制备TiO₂纳米管阵列具有工艺简单、成本低廉、易于放大等优点,引起了极大关注。本文综述了阳极氧化法制备TiO₂纳米管阵列的研究现状,基于TiO₂纳米管阵列在阳极氧化过程中的生长机理,讨论了决定阳极氧化TiO₂纳米管阵列形成的主要因素。结合本组的研究工作,总结了如何通过改变电压、升压速率、电解液、温度和氧化时间,实现纳米管管径、管壁厚度、管长的有效控制,提高TiO₂纳米管阵列的表面形貌质量。最后介绍了TiO₂纳米管阵列掺杂改性方面的研究进展。     

电化学沉积制备半导体CuInSe2薄膜

本文报道恒电位法在pH为1.35的Cu₂SO₄、SeO₂、In₂(SO₄)₃溶液中,在Ti电极上电化学沉积制备CuInSe₂纳米薄膜.研究络合剂柠檬酸和酒石酸对制备CuInSe₂纳米薄膜的影响.扫描电子显微镜(SEM)结果表明,加入络合剂后,电化学沉积的薄膜表面颗粒分布更均匀、致密.X射线衍射(XRD)分析显示,制备的CuInSe₂薄膜是黄铜矿和闪锌矿相的混和物,添加柠檬酸和酒石酸后,衍射峰增强,晶形变好.制备的薄膜颗粒尺寸大小在250nm左右,造成粒度增大的原因是由于颗粒的团聚作用.     

活性碳载体对TiO2光催化降解Cl2CHCOOH性能的影响

研究了活性碳(AC)载体对TiO₂光催化降解Cl₂CHCOOH性能的影响.结果表明,加入AC载体能提高TiO₂的光催化反应速度,而且AC加入方法及含量有明显影响.本文探讨了TiO₂光催化性能提高的原因.     

以十二烷基苯磺酸钠为模型反应物的Y2O3/TiO2复合催化剂的制备及光降解催化性能

采用浸渍法制备了Y₂O₃/TiO₂复合氧化物催化剂,并用紫外可见光谱、SEM、BET等手段对其进行了表征.以水相十二烷基苯磺酸钠(DBS)溶液的光催化降解反应为实验模型,考察了TiO₂掺杂Y₂O₃后的光催化氧化活性,并探讨了Y₂O₃掺杂量、吸附性、焙烧温度及时间对Y₂O₃/TiO₂复合氧化物催化剂光催化活性的影响.实验结果表明:复合氧化物催化剂Y₂O₃/TiO₂存在某一最佳组分比值,当两者重量比为1:200时,其催化活性是同样条件下前体催化剂TiO₂的2.4倍.     

用表面处理法降低TiO2粉末光活性问题的研究

本工作采用了两种简便的方法即用不同金属盐和金属氧化物对两种晶型(锐钛矿型和金虹石型)TiO₂粉末进行表面处理来降低TiO₂的光活性并对两种表面处理方法的优缺点作了比较,在评价TiO₂光活性时采用异丙醇光氧化反应的方法。实验证明,用金属盐表面处理TiO₂,其光活性有明显降低。用金属氧化物对TiO₂进行表面处理,在氧化物/TiO₂比例适当时也可以得到与金属盐表面处理TiO₂的同样效果。此外,我们还对TiO₂表面处理后能降低其光活性的作用机制问题进行了讨论。     

Pr3+掺杂的TiO2纳米粉体的表面特性和光催化活性

利用酸催化的溶胶-凝胶法制备了纯的和不同Pr³⁺掺杂量的TiO₂纳米粉体.以亚甲基蓝(MB)溶液的光催化降解为探针反应,评价了它们的光催化活性.利用XRD和BET技术研究了Pr³⁺掺杂量和焙烧温度对TiO₂纳米粉体的相结构、晶粒尺寸和表面织构特性的影响,并用XPS和SPS技术研究了Pr³⁺掺杂的TiO₂纳米粉体的表面组成和表面光伏特性,探讨了Pr³⁺掺杂提高纳米TiO₂的光催化活性的机制.结果表明:适量Pr³⁺掺杂能显著提高纳米TiO₂的光催化活性.当Pr³⁺掺杂量为1.25%(以Pr³⁺/TiO₂质量比计),焙烧温度为600℃时,制得粉体的光催化活性最佳.Pr³⁺掺杂强烈地抑制TiO₂由锐钛矿相向金红石相的转变,减小晶粒尺寸,增大比表面积,增加表面羟基和吸附氧的含量,提高光生电子和空穴的分离效率,改善粉体表面的光吸收性能,上述因素均有利于光催化活性的提高.     

多晶二氧化钛表面浸润性转变的机械化学处理方法

TiO₂薄膜具有光致超亲水性 ,在黑暗中放置一段时间后转变为疏水性 .本文报道了一种可以在几分钟内实现多晶锐钛矿薄膜表面的亲水性向疏水性转变的机械化学方法.     

纳米TiO2薄膜的制备方法

本文对纳米TiO₂薄膜的各种制备方法，包括基于溶胶－凝胶的涂层方法、电沉积、化学气相沉积、物理气相沉积、自组装制膜，以及喷雾热分解等方法的研究进展进行了综述，对不同方法的优缺点进行了比较和评述，对今后TiO₂薄膜制备的研究方法提出了一些建议。     

Thermogravimetric Study of Volatile Precursors For Chemical Thin Film Deposition. Estimation of vapor pressures and source temperatures

Normal pressure thermogravimetry (TG) measurements were used to study the sublimation behavior of several volatile metal compounds, used as metal precursors in thin film fabrication by chemical vapor phase methods, like atomic layer deposition (ALD) and chemical vapor deposition (CVD). The results indicated that dynamic TG measurements may be used to find correct source temperatures to be used in an ALD reactor: a good correlation between the source temperatures used in ALD and temperatures corresponding to mass losses of 10 and 50% in TG was verified. It was also found that isothermal TG measurements offer a simple way for the vapor pressure measurements which otherwise are not trivial for solids with only moderate volatility. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of temperature on the properties of TiO2 photocatalysts prepared by the chemical vapor deposition (CVD) method

In this study, a TiO₂ film was prepared in an annular reactor by the chemical vapor deposition (CVD) method. Results indicated that anatase crystals were formed, except for at a deposition temperature of 200°C without calcination. At a calcination temperature of 850°C, anatase crystal was the major species formed with a small amount of rutile crystals. After conducting a photocatalytic reaction of toluene, the best activity was found with a preparation temperature of 350°C for the deposition, and 550°C for calcination.     

化学气相淀积法合成氮化铝薄膜及其工艺设计

对ＡｌＢｒ３－ＮＨ３－Ｎ２体系化学气相淀积法合成Ａ１Ｎ膜进行了热力学分析和工艺设计，研究了在不同淀积温度和体系总压时，体系中主要气态物种的平衡分压和Ａ１Ｎ膜的理论淀积速率与源温和载气流量的关系，并与微波等离子体化学气相淀积Ａ１Ｎ膜的实验结果进行了比较。     

Selective Metal‐vapor Deposition on Organic Surfaces

Selective metal‐vapor deposition signifies that metal‐vapor atoms are deposited on a hard organic surface, but not on a soft (low glass transition temperature, low T_g) surface. In this paper, we introduce the origin, extension, and applications of selective metal‐vapor deposition. An amorphous photochromic diarylethene film shows light‐controlled selective metal‐vapor deposition, which is caused by a large T_g change based on photoisomerization, but various organic surfaces, including organic crystal and polymers, can be utilized for achieving selective metal‐vapor deposition. Various applications of selective metal‐vapor deposition, including cathode patterning of organic light‐emitting devices, micro‐thin‐film fuses, multifunctional diffraction gratings, in‐plane electrical bistability for memory devices, and metal‐vapor integration, have been demonstrated.     

Vapor phase oxidative synthesis of conjugated polymers and applications

Since their discovery, electrically conductive polymers have gained immense interest both in the fields of basic and applied research. Despite their vast potential in the fabrication of efficient, flexible, and low‐cost electronic and optoelectronic devices, they are often difficult to process by wet‐chemical methods due to their very low to poor solubility in organic solvents. The use of vapor‐based synthetic routes, in which conductive polymers can be synthesized and deposited as a thin film directly on a substrate from the vapor phase, provides many unique advantages. This article discusses oxidative vapor deposition processes, primarily vapor phase polymerization and oxidative chemical vapor deposition, of conjugated polymers and their applications. The mild operating conditions (near room temperature processing) allow conformal and functional coatings of conjugated polymers on delicate substrates. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

化学气相沉积法制备氮化钛

本文以氮化钛的CVD制备为例,说明了源物质的选择对CVD过程的影响.在此基础上,综述了化学气相沉积技术在材料制备领域的最新进展.     

Plasma chemical vapor deposition of TiN

Experiments indicate that the temperature in chemical vapor deposition (CVD) of TiN can be decreased from about 1000°C in conventional CVD to about 500°C by the application of a D.C. nonequilibrium plasma. The hardness of the TiN film is greater than 2000 kg/mm² (Vickers). The effect of pressure, ratio of gas mixture, and discharge parameters on the film deposition rate, its hardness, and microstructures has been studied.     

Vapor‐Phase Deposition and Modification of Metal–Organic Frameworks: State‐of‐the‐Art and Future Directions

Materials processing, and thin‐film deposition in particular, is decisive in the implementation of functional materials in industry and real‐world applications. Vapor processing of materials plays a central role in manufacturing, especially in electronics. Metal–organic frameworks (MOFs) are a class of nanoporous crystalline materials on the brink of breakthrough in many application areas. Vapor deposition of MOF thin films will facilitate their implementation in micro‐ and nanofabrication research and industries. In addition, vapor–solid modification can be used for postsynthetic tailoring of MOF properties. In this context, we review the recent progress in vapor processing of MOFs, summarize the underpinning chemistry and principles, and highlight promising directions for future research.     

硫/碳纤维复合膜的制备及电化学性能

采用热丝化学气相沉积法先在铁箔上沉积了致密的碳纤维膜,后通过加热渗硫法制得硫/碳纤维复合膜,并将其用作锂硫电池正极材料。通过扫描电子显微镜和X射线衍射表征膜的形貌和结构,采用恒流充放电法和阻抗测量法测试复合膜的电化学性能。结果表明,随热丝与铁箔基底间距减小,碳纤维膜致密度先升高后降低;随H2与(Ar+C3H6O)的体积流量比减小,碳纤维膜致密度升高。当丝基距为6 mm,流量比为30/40时,铁箔上沉积了厚度为50μm的致密碳纤维膜,其中碳纤维有良好的垂直取向性和较高结晶度。在硫/碳纤维复合膜正极中,密集的碳纤维形成均匀分布且垂直取向性良好的导电骨架,当电流密度为0.4 mA.cm-2时,硫/碳纤维复合膜正极的初次放电比容量为1 128 mAh.g-1,50次循环后的放电比容量为811 mAh.g-1。