Preparation of the TiO2 Thin Film Photocatalyst by the Dip-Coating Process

Titanium dioxide (TiO2) coated glass-plate thin film photocatalysts for elimination of air pollutants, were prepared by the dip-coating process with titanium alkoxide including polyethylene glycol (PEG). The surface structure of these thin films changed drastically with the size of the PEG. They were either transparent or opaque. Nitrogen oxides (NOx), one of the most hazardous of air pollutants, were found to be efficiently eliminated by the thin film photocatalyst. The photocatalytic activities of the transparent and opaque thin films were found to be almost equal. This may be due to the two films having the same surface area. The highest activity was obtained for thin films around 1 m.     

TiO2光致双亲性与水性油墨转印的研究

研究了TiO2薄膜作为一种新型印刷材料的浸润性与光照时间和光照强度的关系以及光照时间对水性油墨在薄膜表面吸附的影响,实现了水性油墨由TiO2薄膜向纸张的多次转移.     

氢氧根离子在TiO2薄膜电极上的吸附行为和光氧化动力学

在醇的水溶液中，应用电化学方法研究了OH－在TiO2薄膜电极上的吸附行为和光氧化动力学.实验结果表明，OH－在TiO2表面的吸附模型符合Langmuir等温吸附方程式，其光氧化动力学行为能用Langmuir-Hinshelwood动力学方程来描述.在光强足够大时，光电流和OH－在TiO2表面的吸附浓度成正比，这表明，光生空穴仅氧化吸附于TiO2表面的OH－，同时吸附的水分子则不能被氧化.在醇浓度足够高的溶液中，自由基OH•和电子之间的复合反应几乎不发生，这时整个光氧化反应的速控步骤是光生自由基OH•的生成.     

A Novel Nanocrystalline TiO2 Thin Film Electrodes Prepared at Low Temperature

Nanocrystalline TiO2 thin films were successfully prepared by a new ““water-cooked““ method on both conductive glass substrates and flexible substrates at low temperature. Dye-sensitized solar cells based on these films have exhibited high overall light-to-electricity conversion efficiencies of 4.67 % and 1.94 % on conductive glass substrate and flexible substrate, respectively, under the illumination at 100 mW/cm^2.     

Preparation and Magnetic Properties of Submicron CrO2 Thin Film on Poly-crystal TiO2 Film

The submicron chromium dioxide(CrO₂) thin film was fabricated on a poly-crystal titania(TiO₂) film using Si wafers as substrates by atmospheric pressure chemical vapor deposition(CVD) method. X-Ray diffraction patterns show that the CrO₂ films were pure rutile structure. Scanning electron microscopy(SEM) images indicate that the CrO₂ films consisted of submicron grains with a grain size of 250―750 nm. The magnetic researches reveal that the magnetic easy axis is parallel to the films, and at room temperature, the CrO₂ films show linear magnetoresistance.     

液相沉积法制备光催化活性TiO2膜

锐钛矿型TiO2薄膜;液相沉积法制备光催化活性TiO2膜     

Photostability Study of Nanoporous TiO2 Film Electrodes in Basic Solutions

The nanoporous TiO2 film electrodes have been prepared by a sol-gel deposition process The photostability of the electrodes in basic solutions has been studied. The results show that the photostability of the electrodes decreases rapidly in strong basic solutions with or without methanol. The reaction of holes to O^2- produces active O^2- atoms and the products O^2- atomsoxidize Ti^3 to Ti^4 on TiO2 film surface and subsurface. This results in the TiO2 film electrodes unstable in basic solutions both without methanol and with too low concentration.     

Electronic Structure Effect of Polythiophene Derivatives and Nano N-Zn-Ag/TiO2 on Performance of Organic Thin Film Solar Cell

Nanocrystal N-Zn-Ag/TiO₂ powders were prepared with N-Zn/TiO₂ by photo deposition method. A series of pure polymers P3HT[poly(3-hexylthiophene)], P3OT[poly(3-octylthiophene)], P3DT[poly(3-decylthiophene)] and P3DDT[poly(3-dodecylthiophene)], was synthesized, which were used to synthesize p-n type semiconductor materials P3HT/N-Zn-Ag-TiO₂, P3OT/N-Zn-Ag-TiO₂, P3DT/N-Zn-Ag-TiO₂ and P3DDT/N-Zn-Ag-TiO₂ by in situ che-mical method. X-Ray diffraction(XRD) and infrared(IR) spectroscopy showed the structure of the polymers and complexes. Ultraviolet-visible(UV-Vis) spectra and cyclic voltammograms(CV) showed the optical and electronic performance of the polymers and complexes. Two new single and double organic thin film heterojunction solar cells were prepared with the above mentioned synthesized powders as raw materials. Current-voltage(I-V) measurements indicate that the conversion efficiency of the single organic thin film heterojunction solar cell is higher than that of the double organic thin film heterojunction solar cells. Single organic thin film heterojunction solar cells based on P3DT/N-Zn-Ag-TiO₂ can get a photoelectric conversion efficiency of 0.0408%. The performance of electronic transform between electron donor and acceptor on organic thin film solar cells was researched.     

TiO2光催化薄膜在陶瓷器具上抗菌效果的研究

抗菌薄膜;TiO2光催化薄膜在陶瓷器具上抗菌效果的研究     

光催化活性TiO2薄膜的低温制备

在低温下,将基材浸渍在含配合物,F－离子捕获剂H3BO3,及加有结晶诱导剂锐钛矿TiO2纳米晶的过饱和水溶液中,在基材上沉积锐钛矿型TiO2薄膜.研究了水溶液的浓度、反应物和H3BO3的摩尔比、沉积时间、反应温度等对沉积TiO2薄膜的结构和性能的影响.并用UV Vis、XRD和SEM等对TiO2薄膜的透明性、厚度、物相和形貌等进行了表征.用亚甲蓝的光催化降解,评价了TiO2薄膜的光催化活性.     

Cr掺杂金红石相TiO2(110)单晶薄膜的制备、表征及光催化活性

采用脉冲激光沉积术(PLD)同质外延生长了表面原子级平整的6%(原子比)Cr 掺杂的金红石相TiO₂(110)单晶薄膜, 采用扫描隧道显微镜(STM)、扫描隧道谱(STS)、X 射线光电子能谱(XPS)和紫外光电子能谱(UPS)对其进行了表征. 结果表明: Cr 掺杂对TiO₂(110)-(1×1)表面的形貌没有明显影响, 但是提高了掺杂薄膜在负偏压的导电性; Cr与晶格O键合而呈现+3价态, 由此在TiO₂的价带顶上方~0.4 eV处引入杂质能级. 紫外-可见光吸收谱显示薄膜的光吸收能力被扩展到~650 nm, 处于可见光范围. 借助STM以单个甲醇分子的光解反应检测了薄膜的光催化活性. 仅观察到紫外光照射下甲醇分子的脱氢反应, 在可见光照射下(λ>430 nm)甲醇分子没有发生反应, 表明单独的Cr掺杂可能不足以提高TiO₂在可见光下的催化活性.     

TiO2 Thin Film with Varied Porous Structure Applied on the Degradation of Methylene Blue

In this study, porous TiO₂ thin films were prepared by the sol‐gel method employing polyethylene glycol 1000 (PEG 1000) as an organic template. Pore sizes were adjusted by varying the concentration of PEG 1000. The optimal PEG concentration range required to form TiO₂ films with a regular porous structure was investigated and was found to be 0.01–0.015 M. As the PEG 1000 concentration increased, the surface of these films became rougher because of larger pores. Degradation of methylene blue (MB) under UV irradiation was used to determine the photocatalytic activity of the films. In addition, the effect of the pH value of the MB solution on the films was evaluated by controlling its pH value at 5, 7, and 9. The results showed that the photocatalytic activity was correlated to the pore size and pore density of the thin films. TiO2 thin films possessing pore sizes in the diameter range of 35–85 nm exhibited the best conversion of 98% after 8 h of UV irradiation when the pH value was 7.     

用模板法制备TiO2纳米线阵列膜及光催化性能的研究

用溶胶-凝胶技术在多孔阳极氧化铝模板的有序微孔内制备了高度取向的TiO2纳米线阵列膜光催化剂.用XRD,AFM和SEM等手段对样品进行了表征.结果表明,TiO2纳米线阵列膜晶型为锐钛矿,从AFM图像中可以看出TiO2纳米线线径分布均匀一致,取向性极好,直径与AAO模板的孔径大小一致.以其对吖啶橙的降解效果作为评价光催化活性的标准,与相同条件下制备的TiO2/玻璃膜相比,TiO2纳米线阵列膜具有很好的催化活性.     

制备条件对二氧化钛薄膜性能的影响(英文)

用低压化学气相沉积法制备ＴｉＯ２薄膜。研究表明,水的分压、沉积温度、基片材料均对沉积速率有影响。在硅片上镀膜,沉积温度相同而退火温度不同,则薄膜结构亦不同。当退火温度高于８５℃时,薄膜为纯金红石薄膜。     

染料敏化太阳能电池用TiO2薄膜电极的改性制备及光电化学性能

以钛酸四异丙酯为钛源, 用水热法合成制备了具有典型锐钛矿晶型的TiO2纳米材料. 采用金属镍掺杂和表面包覆一层氧化钕, 对TiO2薄膜电极进行改性研究. 实验结果表明, 所制备纳米TiO2颗粒较均匀, 粒径约为17~18 nm. 经镍掺杂后, 颗粒团聚粒径明显增大, 但是仍保持均匀状态和多孔结构. 与改性前的TiO2薄膜电极相比, 金属掺杂和表面包覆有助于光生电子和空穴有效地分离, 电池的短路光电流提高了16%, 光电转换效率提高了17%.     

不同波长紫外光照下纳米TiO2薄膜的光致亲水性与循环伏安行为

通过溶胶-凝胶方法分别在ITO和玻璃表面制备了纳米TiO_2薄膜，研究了纳米 TiO_2薄膜在254及365nm的紫外光照射下的循环伏安行为和光致超亲水性。在紫外 光的照射下，TiO_2薄膜电极可表现出两个光电化学过程，纳米TiO_2薄膜的光致超 亲水性转变及两个光电化学过程的速率均取决于紫外光的波长，原因在于纳米 TiO_2薄膜对两种波长的光的吸收率和光子的能量不同。提出了光电化学过程的机 理，认为紫外光照射下纳米TiO_2薄膜的超亲水性变化与产生Ti~(3+)的过程引起的 表面微观结构变化存在的一定的内在联系。     

微乳-水热法制备具有自清洁功能的TiO2薄膜

采用热陈化微乳液及浸渍-提拉技术,制备了具有自清洁功能的TiO2薄膜。 考察了微乳液中表面活性剂十二烷基苯磺酸（DBS）的用量对TiO2薄膜的表面形态和微观结构的影响。 进而对合成的TiO2薄膜的光催化活性、光致亲水性能及实际环境中的自清洁效果进行了测试评价。 随着表面活性剂DBS用量的增加,微乳液中的分散质点尺寸减小,但热陈化后所获得的TiO2粒子表现出凝集现象。 在DBS用量为0及58 mg/L时,所获得薄膜表面较为平整,由15~20 nm大小的TiO2粒子组成。 这些薄膜在无紫外光照射时,水接触角增大的速度较慢,并且在紫外光照射下能迅速恢复其超亲水性能。 将薄膜置于室外25 d后其表面无灰尘粘结,水接触角由原来的0°增大至14°~18°。 当DBS用量为580 mg/L以上时,薄膜表面起伏不平,粗糙度过大,对应TiO2薄膜光致亲水性能较差,室外放置25 d后,水接触角由原来的0°增大至46°~48°。     

图案化TiO2薄膜的制备技术

本文综述了图案化TiO2薄膜的制备技术,按图案的生成方式可分为图案的直接生成,掩膜复制法,硬质模板复制法三大类。可以通过针尖写蚀法、电子书写蚀法、激光写蚀法、自组装法、光电化学法直接制备图案。掩膜复制法包括光刻胶法、自组装膜法、光敏凝胶膜法等。硬质模板法也称软刻蚀技术,分为复制微模塑、转移微模塑、毛细管微模塑、微接触印刷法、光-盖印印刷等技术。对每类方法的优缺点作了适当评述,对今后图案化TiO2薄膜制备的研究方向提出了一些建议。     

马来酸在束状TiO2阳极氧化膜上的电催化还原

采用阳极氧化法在0.5 mol·L-1硫酸+1 mol·L-1马来酸的混合溶液中制得了束状TiO2薄膜.X射线衍射(XRD)分析表明样品的晶型结构主要为无定形态;所制得的样晶通过原子力显微镜(AFM)观察,束状结构TiO2的宽度约2-5μm,长度超过20μm,束状结构中包含的纳米棒直径约80-150 nm.将制得的束状TiO2膜电极在上述混合溶液中直接进行原位的循环伏安扫描和恒电流电解实验.研究结果表明,马来酸在该电极表面异相电催化还原生成丁二酸;在恒电流电解过程中采用电极原位活化可明显提高丁二酸的产率和电流效率,并指出改进电极的原位活化技术是未来研究工作的主要目标.     

Relationship Between Photocatalytic Activity and Structure of TiO2 Thin Film

TiO2 thin films with different crystalline structures were prepared by the CVD method. The relationship between photocatalytic activity of a TiO2 thin film and its crystalline type was investigated. These films were characterized by XRD and AFM. Their photocatalytic properties were tested by the degradation of NO2-. The results showed that the crystalline structures of TiO2 thin films are primary anatase and/or rutile when the preparation temperatures were less than 573 K and higher than 773 K respectively. When the preparation temperature was around 623 K, the structures of TiO2 thin films were mixed crystalline structure, which showed the highest catalytic activity. When the ratio of rutile to anatase in TiO2 thin films fell between 0.5 and 0.7, the highest catalytic activity for the degradation of NO2- was found.