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1.
TiO2 fibers were prepared via alternatively introducing water vapor and Ti precursor carried by Ne to an APCVD (chemical vapor deposition under atmospheric pressure) reactor at <200 ℃. Activated carbon fibers (ACFs) were used as templates for deposition and later removed by calcinations. The obtained catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brtmauer, Emmett and Teller (BET) and X-ray diffraction (XRD) analysisThe pores within TiO2 fibers included micro-range and meso-range, e.g., 7 nm, and the specific surface areas for TiO2 fibers were 141 m2/g and 148 m2/g for samples deposited at 100 ℃ and 200 ℃ (using ACF1700 as template), respectively. The deposition temperature significantly influenced TiO2 morphology. The special advantages of this technique for preparing porous nano-material include no consumption of organic solvent in the process and easy control of deposition conditions and speeds. 相似文献
2.
水解沉淀法制备纳米TiO2及其表征 总被引：1，自引：0，他引：1
以TiOSO4为原料制备纳米TiO2 并对其进行XRD、BET、TEM研究 .结果表明 ,pH值与热处理温度对晶粒大小及晶型结构有很大影响 .在 5 0 0℃热处理条件下 ,pH =5时的纳米粉末比表面积为 10 1.3 9m2 ·g-1,粒径 10nm左右 ;pH =10时的纳米粉末比表面积为 95 .48m2 ·g-1,粒径 3 0nm左右 .在 75 0℃时的金红石晶型转变对粒径的长大有很大的促进作用 . 相似文献
3.
以孔径为80 nm的大孔有序碳材料（C80）为基体,采用98％ HNO3浸泡氧化改性,研究酸化对多孔碳成分、结构与电化学性能的影响.结果表明：经98％ HNO3氧化改性,多孔碳的孔壁发生膨化,比表面积减小,表面含氮、氧官能团含量增加,进而导致其电化学性能也大幅度地提高;在1 mol/LH2 SO4电解液中,酸化后多孔碳的比电容可达177.6 F/g（电流密度为0.1A/g）,与同一电流密度下的C80相比,比电容提高了50F/g;而以6 mol/L KOH做电解液,比电容提高了36.85 F/g. 相似文献
4.
STABILIZED ZNTIO, WAS PREPARED BY DOPING MAGNESIUM OXIDE THROUGH TRADITIONAL SOLID-STATE REACTION. THE EXPERIMENTAL RESULTS INDICATE THAT ZINC TITANATE CRYSTALS DOPED WITH MAGNESIUM OXIDE GROW WELL AND THE DECOMPOSITION INTO ZN2TIO4 AND TIO2 IS RESTRAINED THROUGH TRADITIONAL SOLID STATE REACTION. BY ADJUSTING MOLAR RATIO OF MGO, BETTER PROPERTIES CAN BE OBTAINED. THE DIELECTRIC PROPERTIES OF THE CERAMICS DOPED WITH 30% MGO( MOLAR PERCENTAGE) SINTERED AT 1 060 ℃ ARE AS FOLLOWS:THE VALUE OF QUALITY FACTOR IS GREATER THAN 20 000(6. 5 GHZ), THE TEMPERATURE COEFFICIENT OF RESONANCE FREQUENCY IS ABOUT 2 × 10-6/℃, THE DIELECTRIC CONSTANT RANGES FROM 18 TO 22. BESIDES, IT IS PROVED THAT HEAT TREATMENT CAN OPTIMIZE MICROSTRUCTURE AND THE VALUE OF QUALITY FACTOR, WHICH INCREASES FROM 23 833.93 TO 47 584.00 AFTER 2 H OF HEAT TREATMENT AT 1 040 ℃. 相似文献
5.
采用溶胶一凝胶法在玻璃基片上制备了TiO：多孔薄膜,主要研究了pH值、模板剂以及乙醇添加量对溶胶和多孔膜性能的影响．研究结果表明：溶胶一凝胶制备过程中,pH一3时和以聚乙二醇～1000为模板剂可得到稳定的溶胶,且n（PEO-1000）／n（Ti）为0．050时所得到的溶胶颗粒最小,团聚最轻,由其可制备出结构均一性好、无开裂的多孔膜;n（CH3CH2OH）／n（Ti）为24：1时,溶胶可在玻璃基体上形成完整的膜,烧结过程中随着聚乙二醇分解的CO2和H2O的逸出形成了许多微孔,得到完整的有序多孔TiO2薄膜。 相似文献
6.
利用磁控溅射技术在玻璃基片上分别沉积ZnOx薄膜、TiO2-y薄膜和TiO2-y/ZnOx双层透明薄膜,改变薄膜沉积过程中的氩气(Ar)和氧气((O2)的比例,获得具有不同氧含量的ZnOx薄膜和TiO2-y薄膜.采用椭偏仪测定所有样品的折射率,仔细研究薄膜中氧含量对折射率的影响.分别选择具有较大的折射率TiO2-y薄膜和具有较小的折射率ZnOx薄膜的生长条件,制备TiO2-y/ZnOx双层薄膜,获得光密媒质/光疏媒质双层结构,并观察到He-Ne激光从ZnOx薄膜入射到TiO2-y/ZnOx界面上发生的全反射现象.研究成果适用于大学生物理实验中的研究型实验或大学创新实验. 相似文献
7.
研究了以稀土复合固体超强酸SO42-/TiO2/Ce4+为催化剂合成乙酸环己酯的反应,在反应温度分别为100℃、110℃、120℃下,测出酯化反应的动力学参数,建立了动力学方程,并与无催化剂作用下合成乙酸环己酯反应的活化能及动力学方程进行了比较.实验结果表明,该催化酯化反应的优化合成条件是:乙酸用量为0.262 1mol时,醇酸摩尔比为1.5:1,催化剂用量为1.0g,带水剂环己烷的加入量为12mL.稀土复合固体超强酸SO42-/TiO2/Ce4+可使反应的活化能明显降低,是合成乙酸环己酯的有效催化剂. 相似文献
8.
稀土钐改性TiO2光催化性能有很大的争议，基于此采用溶胶-凝胶法制备了不同掺杂量和不同温度下煅烧的光催化剂，通过XRD和亚甲基蓝的降解实验，探讨了煅烧温度、空气流速、催化剂用量和掺杂量对亚甲基蓝的降解效果。结果表明：当煅烧温度为500℃，掺杂Sm^3＋为1．2％，空气流速达到1．3L／min，催化剂用量为1．5g／L时，催化性能达到最好。 相似文献
9.
采用等离子体增强化学气相沉积技术制备了硼掺杂氢化非晶硅薄膜,然后经过不同温度的热退火处理,获得硼掺杂纳米硅薄膜．结果表明,退火温度为700℃时,样品中开始有纳米晶形成,随着退火温度的增加,在1000℃时,薄膜的晶化率达到77％,晶粒大小为3．9nm．退火温度低于600℃时,光学带隙随着退火温度的升高而变窄,高于600℃... 相似文献
10.
在含有0.2 mol.L-1苯胺的0.5mol.L-1H2SO4溶液中,采用循环伏安法(CV),以扫描速度50mv.s-1,扫描电位为-0.1～0.9V,在碳纳米管/纳米TiO2(CNT/nanoTiO2)膜电极上实现了苯胺的电化学聚合,并通过扫描电镜对膜层的微观形貌进行观察,发现这种在纳米基体上聚合得到的聚苯胺膜呈疏松、多孔的纳米纤维网状结构,不同于在金属基体上聚合得到的颗粒状聚苯胺膜. 相似文献
11.
王爽 《天津职业技术师范学院学报》2010,(1):12-14,68
对稀土氧化物CeO2掺杂的BaTiO3系统微观结构和介电性能进行了研究。结果表明,在BaTiO3陶瓷中掺杂CeO2会产生细晶效应、介电常数增大以及介电损耗减小等现象。由X射线衍射仪（XRD）计算可知,c轴变长,a轴变短,增强,Ti^4＋“自发极化强度,因而介电常数有所提高。由于Ce^4＋离子进行A位取代,Ce^4＋离子半径（0．103nm）小于Ba^2＋离子半径（0．135nm）,导致晶格常数有所减小,居里温度向低温移动。掺杂CeO2的摩尔分数为0．5％的BaTiO3陶瓷在1240℃下烧成的主要性能指标为：室温介电常数ε25℃≈3160,介电损耗-0．9％,-55℃到125℃范围内最大电容量变化率不超过±15％。 相似文献
12.
量子尺寸TiO/SiO2复合微粒的制备与光催化性能研究 总被引：1，自引：0，他引：1
采用改进的溶液－凝胶方法，制备出TiO2及不同配比的TiO2／SiO2粉末，利用XRD，BET，UV－vis等手段研究了微粒的表面结构形态变化，以及对污染物NO2^-光催化降解的影响。研究表明，TiO2／SiO2复合微粒的光催化活性明显高于TiO2微粒，并且质量比m(Ti):m(si)=2:1时催化降解NO2^-最佳。制得TiO2微粒以锐钛型高度分散在TiO2网络中，粒径约12nm，并与TiO2形成Si-O-Ti桥氧结构，提高了TiO2微晶的热稳定性，UV－vis吸收光谱显示复合微粒的光谱吸收发生蓝移，极利于吸附降解NO2^-。 相似文献
13.
稀土掺杂纳米TiO2的合成研究 总被引：1，自引：0，他引：1
以钛酸四丁酯和硝酸钇为原料 ,采用溶胶—凝胶法制备了掺杂Y的TiO2 纳米材料 ,通过XRD、TEM对产物的晶体结构、晶粒大小、形貌进行了表征 ,TG -DTA研究了TiO2 在锐钛型和金红石型之间的晶型转变过程。结果表明 ,产物为纳米微粒 ,平均粒径为 30nm左右。 相似文献
14.
周小龙 《湖州师范学院学报》2012,34(1):45-48
提出了一种新的催化剂制备方法,采用TiO2纳米棒与聚乙二醇通过压片和焙烧的方法制备了多孔TiO2块体.通过条件优化,当纳米棒与聚乙二醇比例为1/3时,成块结构良好,且光催化反应前后保持了完整的块体结构,制备的块体降解甲基橙2h达到74.77%,具有良好的光催化活性,且在非均相光催化应用中催化剂无需分离,从而解决了催化剂的回收问题. 相似文献
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16.
Nano-particles lanthanum-modified lead titanate (PLT) thin films are grown on Pt/Ti/SiO2/Si substrate by liquid source misted chemical deposition (LSMCD). PLT films are deposited for 4-8 times, and thenannealed at various temperature. XRD and SEM show that the prepared films have good crystallization behavior and perovskite structure. The crystallite is about 60nm. The deposition speed is 3nm/min. This deposition method can exactly control stoichiometry ratios, doping concentration ratio and thickness of PLT thin films. The best annealing process is to bake at 300℃ for 10min and anneal at 600℃ for 1h. 相似文献
17.
纳米级ZnO-TiO2复合粉体的制备及其性能研究 总被引：2，自引：0，他引：2
利用ZnCl2,TiCl4为原料，用共沉淀法合成了ZnO-TiO2复合粉体，采用XRD、TEM和IR测试手段对纳米级的粉体结构和形貌进行研究，结果表明，通过控制反应条件可得到粒径为10－40nm的复合粉体。利用紫外－－可见分光光工地检测所得样品的吸收紫外线性能，发现所得纳米ZnO-TiO2复合粉体的紫外吸收性能高于纳米TiO2及市售微米级钛白粉，且纳米ZnO-TiO2复合粉体的紫外吸收随粒径的减小而加强。 相似文献
18.
Pt/Ti bottom electrodes were fabricated on SiO2/Si substrates by magnetron dual-facing-target sputtering system. Lead zirconate titanate(PZT) thin films were deposited on Pt/Ti/ SiO2/Si substrates by radio frequency (RF) magnetron sputtering system. The thickness of PZT thin films which were deposited for 5 h was about 800 nm. XRD spectra show that PZT thin films deposited in Ar ambience and rapid-thermal-annealed for 20 min at 700 ℃ have good crystallization behavior and perovskite structure. AFM micrographs show that mean diameter of crystallites is 70 nm and surface structures of PZT thin films are uniform and dense. Raw mean, root mean square roughness and mean roughness of PZT thin films are 34.357 nm, 2.479 nm and 1.954 nm respectively. As test frequency is 1 kHz, dielectric constant of PZT thin films is 327.6. Electric hysteresis loop shows that coercive field strength, residual polarization strength and spontaneous polarization strength of PZT thin films are 50 kV/cm, 10 μC/cm2 and 13 μC/cm2 respectively. 相似文献
19.
MBE growth of ZnSxSe1-x thin films on ITO coated glass substrates were carried out using ZnS and Se sources with the substrate temperature ranging from 270℃ to 330℃. The XRD θ/2θ spectra resulted from these films indicated that the as-grown polycrystalline ZnSxSe1-x thin films had a preferred orientation along the (111) planes. The evaluated crystal sizes as deduced from the FWHM of the XRD layer peaks showed strong growth temperature dependence, with the optimized temperature being about 290℃. Both AFM and TEM measurements of these thin films also indicated a similar growth temperature dependence. High quality ZnSxSe1-x thin film grown at the optimized temperature had the smoothest surface with lowest RMS value of 1.2 nm and TEM cross-sectional micrograph showing a well defined columnar structure. 相似文献
20.
The effects of particle size of activated carbon （AC） on its wettability, electrode coating technology and electric chemical performance were studied to assemble nonaqueous electric double layer capacitors （EDLCs） for high power requirements. The results show that the specific surface area and total pore volume of AC decrease from 2 137 m^2/g to 1 683 m^2/g, and 0.95 cm^3/g to 0.78 cm^3/g, respectively, if it is ball-milled for 8 h. The pore size distributions are similar in the range of 0.7 nm to 3.5 nm for different ball-milling time. There exists oxidation on the surface of AC during the ball-milling process and the ratios of O-C=O oxygen compositions increase whereas those of C-O, C=O decrease. The peeling strength of AC coated on current collector is almost inverse proportion with the particle size of AC as well as the resistance of EDLCs, and its capacitance decreases about 6%. 相似文献