TiO_2纳米管阵列电极染料敏化太阳能电池

采用电化学阳极氧化法在纯钛片表面制备了高度有序的TiO2纳米管阵列。利用SEM、XRD分别对TiO2纳米管阵列的形貌、晶型进行了表征,并通过线性扫描伏安法对N719染料敏化纳米管阵列电极的光电性能进行了研究。实验结果表明,纳米管阵列的管径和长度随着阳极氧化电压的升高和氧化时间的延长都分别相应增加。同时还发现,通过450℃热处理的TiO2纳米管阵列,具有较好的锐钛矿晶型结构,其光电转化效率为2.1%。     

TiO2纳米管在太阳能电池中的应用新进展

回顾了近年来TiO2纳米管阵列在染料敏化太阳能电池中的应用现状和最新研究成果,综述了影响染料吸附量和电池效率的一些关键因素,包括管几何结构(长度、直径、顶部形态)、晶体结构(无定形、锐钛型、金红石型),以及表面改性、染料浸润敏化时间、温度和先进结构.当考虑所有这些因素时,现在纯纳米管体系太阳能电池的最高效率可以达到4％～5％,一些混合系统可以达到7％左右.还讨论了这两种体系现在存在的主要问题和提升的空间,并概述了今后的改进策略.     

MoS2修饰TiO2纳米管阵列光电化学性能研究

通过阳极氧化法在乙二醇电解液中制备TiO₂纳米管阵列, 以钼酸钠和硫脲作为钼源和硫源, 并添加半胱氨酸为辅助剂, 水热法制备纳米花状二硫化钼修饰的TiO₂纳米管阵列。用X射线衍射仪、扫描电子显微镜、能谱仪和拉曼光谱对复合材料的晶型、形貌、物相等进行分析, 通过电化学工作站测试复合材料的线性扫描伏安曲线、电化学阻抗谱和莫特-肖特基曲线。结果表明: MoS₂/TiO₂复合材料形貌比较规整均匀, MoS₂纳米花尺寸约为200 nm; MoS₂与TiO₂复合有利于形成异质结, 促进光生电子和空穴的分离; 当钼酸钠浓度为0.8 mmol/L时制备的复合材料光化学能转化率为纯氧化钛的2.89倍, 达到了1.65%, 而且复合材料的电荷转移电阻降低了约50%, 光生载流子浓度提高了24倍, 达到了3.38×10²³ cm^-3, 具有非常优异的光电化学性能。     

聚苯乙烯和聚乙二醇对TiO2薄膜微观结构及DSSC性能的影响

用水热法制备了多孔TiO2光电薄膜;分析了聚苯乙烯和聚乙二醇对纳米TiO2晶体薄膜微观结构的影响;用紫外-可见-近红外分光光度计和场发射扫描电镜对纳米TiO2薄膜进行了表征;并对组装的染料敏化太阳能电池进行了光电性能测试,发现用聚苯乙烯处理后的TiO2薄膜提高了染料敏化太阳能电池(DSSC)的开路电压、短路电流密度、填充因子和光电转换效率.     

TiO2纳米管阵列在太阳能电池中应用的研究进展

综述了TiO2-NTAs太阳能电池的最新进展,分析了TiO2-NTAs太阳能电池的特点,并展望了TiO2-NTAs太阳能电池的研究方向.     

自持TiO2纳米管阵列薄膜与TiO2/FTO透明光电极制备工艺的研究

利用电化学阳极氧化法,采用三步氧化工艺,成功制备出大面积高度有序、孔洞分布均匀、孔道垂直取向且与金属钛基相分离的自持TiO2纳米管阵列膜。然后将其转移粘接至FTO导电玻璃上,形成高度有序的TiO2/FTO纳米管阵列透明光电极。利用场发射扫描电镜、X射线衍射仪、紫外-可见-近红外分光光度计分别对样品的形貌、晶相结构以及光学特性做了表征。研究表明,由三步阳极氧化工艺制备的自持TiO2纳米管阵列膜,其结构参数（如管径、管长及管壁厚度）在很大范围内可控,将其转移粘结至FTO导电玻璃上能制成多种用途的高质量透明光电极;另外,阳极氧化电压对TiO2纳米管阵列薄膜的光学能隙（Eg）也有较为明显的调制作用。显然,这项新工艺对基于TiO2纳米有序阵列复合结构的有机-无机光电器件的应用研究将是非常有益的。     

V掺杂TiO2纳米管阵列的制备及光催化研究

以钒钛合金为原料,应用阳极氧化法制备出高度致密、有序的V掺杂TiO2纳米管阵列。应用扫描电镜(SEM)和粉末X光衍射仪(XRD)表征分析纳米管阵列的形貌和结构,结果表明在浓度不同的HF电解液下制备出径向不同的纳米管阵列,电解液浓度(0.5%～1.5%(质量分数)),管径变化(39.7～72.7nm)。在室温、可见光照射条件下,以10mg/L的亚甲基蓝溶液为模拟污染物进行光催化降解试验,研究了其光催化性能。结果显示V掺杂TiO2纳米管阵列光催化性能优于纯TiO2纳米管,且在HF电解液浓度为1.0%(质量分数)时制备出来的TiO2纳米管光催化降解有机毒物性能最佳。     

玻璃基底TiO2纳米管阵列的制备及其光电性能研究

提高二氧化钛纳米管阵列电极的机械稳定性,改善电极的透光性能,有助于提高其光电催化性能,拓展电极的应用范围.通过室温射频溅射方法在玻璃基底上溅射一层金属钛膜,然后在含0.5%HF的电解液,10V阳极氧化电压下进行阳极氧化,得到玻璃基TiO2纳米管阵列电极.扫描电子显微镜和X射线衍射分析表明,玻璃基表面形成了孔径为20～30nm,管长约130nm排列有序的锐钛矿型TiO2纳米管阵列.光电性能测试表明,玻璃基TiO2纳米管阵列与金属钛基TiO2纳米管阵列表现出相似的光电催化性能,明显优于磁控溅射制备的TiO2薄膜.     

阳极氧化法制备TiO2纳米管阵列及其光电性能研究

采用阳极氧化法在钛片上制备了TiO2纳米管阵列光电极，利用扫描电子显微镜（SEM）和X射线衍射仪（xRD）对TiO2纳米管的形貌和结构进行了表征，详细考察了氧化工艺参数对纳米管阵列形貌的影响，并通过稳态光电响应技术对TiO2纳米管电极的光电化学性能进行了研究．结果表明，在1wt％HF电解液中，控制氧化电压为20V，反应30min后，在Ti表面获得了垂直导向的TiO2纳米管阵列，孔径约为90nm，管壁厚度约为10nm．经600℃退火处理后，TiO2纳米管阵列为锐钛矿型与金红石型的混晶结构，此时电极的光电性能最佳，与TiO2纳米多孔膜电极相比，光电性能大幅提高．     

柔性TiO2薄膜电极的制备方法及其对光电性能的影响

分别采用水热法和紫外处理低温烧结法制备了柔性TiO2薄膜电极。通过傅立叶变换红外吸收光谱仪（FTIR）、紫外可见光仪（UVSP）、场发射扫描电镜（FESEM）对两种方法制备的TiO2薄膜电极进行表征，同时，测试了不同电极组装柔性染料敏化太阳能电池的光电性能。结果表明：两种方法制备的电极均为一种多孔结构，不含有机物；紫外处理低温烧结法制备电极组装柔性电池的短路电流为4.9mA，其光电转换效率为1．28％。而水热法制备电极组装柔性电池的稳定性较好，虽然其短路电流为2．60mA，光电转换效率为1．32％。     

三电极体系制备TiO2纳米管

利用电化学阳极氧化法在乙二醇和氟化铵溶液三电极体系中阳极氧化纯钛箔,制备出具有双面结构的TiO2阵列纳米管。研究了不同电压和电解液含水量对纳米管形貌的影响,通过扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析了TiO2纳米管阵列的微观形貌及物相。     

铜掺杂TiO_2纳米管阵列的制备与光催化还原性能

以阳极氧化法制得的TiO2纳米管阵列为前驱体,用浸渍法制备了不同铜掺杂量的TiO2纳米管阵列。采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)、X光电子能谱(XPS)、荧光光谱(PL)对样品进行表征。以Cr6+水溶液为目标污染物,对比不同铜掺杂量TiO2纳米管阵列的光电催化还原效果。结果表明,掺杂前后TiO2纳米管阵列在形貌上没有明显变化;掺杂的铜是以Cu2+的形态存在;掺铜后TiO2纳米管阵列还原效果优于掺铜前;低剂量铜掺杂的TiO2纳米管阵列的还原效果优于高剂量铜掺杂的TiO2纳米管阵列。     

CdS/TiO_2纳米管阵列的制备及其光电催化活性研究

利用阳极氧化法和电沉积法制备CdS修饰的TiO2纳米管阵列。应用FE-SEM、XRD、DRS和LSV(线性伏安扫描)对该阵列的形貌、晶型、光学性质和光电性能进行表征,并研究该阵列降解亚甲基蓝的光电催化活性。结果表明,CdS以颗粒形式存在于TiO2纳米管阵列表面,CdS/TiO2纳米管阵列在可见光处有较强吸收,有较大光响应电流,其光电催化活性优于纯TiO2纳米管阵列。     

阳极氧化TiO2基纳米管阵列的应用研究进展

阳极氧化TiO2纳米管阵列由于具有独特的高度有序的纳米结构和优异的物理化学性能,在许多研究领域都具有广阔的应用前景,已成为纳米材料以及太阳能光转化利用等研究领域的热点之一,受到国内外的广泛重视.针对TiO2基纳米管阵列薄膜材料,综述了其在主要应用领域的研究进展,分析了存在的主要问题,提出了今后的发展方向.     

Preparation of near micrometer-sized TiO2 nanotube arrays by high voltage anodization

Highly ordered TiO₂ nanotube arrays with large diameter of 680–750 nm have been prepared by high voltage anodization in an electrolyte containing ethylene glycol at room temperature. To effectively suppress dielectric breakdown due to high voltage, pre-anodized TiO₂ film was formed prior to the main anodizing process. Vertically aligned, large sized TiO₂ nanotubes with double-wall structure have been demonstrated by SEM in detail under various anodizing voltages up to 225 V. The interface between the inner and outer walls in the double-wall configuration is porous. Surface topography of the large diameter TiO₂ nanotube array is substantially improved and effective control of the growth of large diameter TiO₂ nanotube array is achieved. Interestingly, the hemispherical barrier layer located at the bottom of TiO₂ nanotubes formed in this work has crinkles analogous to the morphology of the brain cortex. These structures are potentially useful for orthopedic implants, storage of biological agents for controlled release, and solar cell applications.     

Hydrogenated TiO2 nanotube arrays for supercapacitors

We report a new and general strategy for improving the capacitive properties of TiO(2) materials for supercapacitors, involving the synthesis of hydrogenated TiO(2) nanotube arrays (NTAs). The hydrogenated TiO(2) (denoted as H-TiO(2)) were obtained by calcination of anodized TiO(2) NTAs in hydrogen atmosphere in a range of temperatures between 300 to 600 °C. The H-TiO(2) NTAs prepared at 400 °C yields the largest specific capacitance of 3.24 mF cm(-2) at a scan rate of 100 mV s(-1), which is 40 times higher than the capacitance obtained from air-annealed TiO(2) NTAs at the same conditions. Importantly, H-TiO(2) NTAs also show remarkable rate capability with 68% areal capacitance retained when the scan rate increase from 10 to 1000 mV s(-1), as well as outstanding long-term cycling stability with only 3.1% reduction of initial specific capacitance after 10,000 cycles. The prominent electrochemical capacitive properties of H-TiO(2) are attributed to the enhanced carrier density and increased density of hydroxyl group on TiO(2) surface, as a result of hydrogenation. Furthermore, we demonstrate that H-TiO(2) NTAs is a good scaffold to support MnO(2) nanoparticles. The capacitor electrodes made by electrochemical deposition of MnO(2) nanoparticles on H-TiO(2) NTAs achieve a remarkable specific capacitance of 912 F g(-1) at a scan rate of 10 mV s(-1) (based on the mass of MnO(2)). The ability to improve the capacitive properties of TiO(2) electrode materials should open up new opportunities for high-performance supercapacitors.     

阳极氧化法制备TiO2纳米管阵列

采用阳极氧化法在乙二醇体系电解液中制备TiO2纳米管阵列,获得了长度为15~20μm的底端纳米管与顶端纳米线的新型复合结构。讨论了电解液中不同含水量对该复合结构形成的影响,并采用两步阳极氧化法对该结构的形成机理进行了分析。结果表明,当乙二醇体系电解液含有0.4%(质量分数)NH4F和2%(体积分数)H2O时,电解液腐蚀速度适中,纳米管上端部分被选择性腐蚀,最终形成纳米管与纳米线的复合结构。     

Super-long aligned TiO2/carbon nanotube arrays

5?mm long aligned titanium oxide/carbon nanotube (TiO(2)/CNT) coaxial nanowire arrays have been prepared by electrochemically coating the constituent CNTs with a uniform layer of highly crystalline anatase TiO(2) nanoparticles. While the presence of the TiO(2) coating was confirmed by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and x-ray diffraction, the resultant TiO(2)/CNT coaxial arrays were demonstrated to exhibit minimized recombination of photoinduced electron-hole pairs and fast electron transfer from the long TiO(2)/CNT arrays to external circuits. This, in conjunction with the aligned macrostructure, facilitates the fabrication of TiO(2)/CNT arrays for various device applications, ranging from photodetectors to photocatalytic systems. Thus, the millimeter long TiO(2)/CNT arrays represent a significant advance in the development of new macroscopic photoelectronic nanomaterials attractive for a variety of device applications beyond those demonstrated in this study.     

Fabrication and photoluminescence properties of ridged TiO2 nanotube arrays

Highly-ordered ridged TiO₂ nanotube (TNT) arrays have been fabricated by a simple anodic method. Their structures have been systematically investigated using X-ray diffractometer, scanning electron microscope, energy dispersive spectrometer and HRTEM, and the results clearly presented the ridged morphologies with the outer diameters of about 200 nm. We also found that the annealing procedure induced the phase transformation from amorphous phase to anatase phase. The room-temperature photoluminescence (PL) properties were studied, and the much stronger PL emission for the anatase phase was observed compared to the amorphous counterparts. Furthermore, the broad emission for the anatase phase could be decomposed of three peaks locating at 540, 622 and 773 nm, respectively. The oxygen vacancies and the trapping of free excitons by TiO₆ octahedra near defects are the key factors to cause these peaks.     

Enhanced hydrogen production on porous TiO2 nanotube arrays

Well aligned TiO2 nanotube arrays have been synthesized via anodization in an NH4F and ethylene glycol electrolyte; the resulting carbon-entrained films were treated by oxygen and argon microwave plasma. It was found that as-prepared amorphous TiO2 nanotubes can be easily crystallized into anatase at temperature lower than 150 degrees C. Carbon can be effectively eliminated in oxygen plasma and a new secondary porosity was emerged. It was found such a porous film has obvious photovoltaic and hydrogen production enhancement under simulated solar irradiation compared with that crystallized in inert argon plasma. This phenomenon may be attributed to the improvement of light adsorption and its excellent capability of hole-electron separation derives from highly ordered nanoporous configurations.