Ag-TiO2复合纳米颗粒的自组装法制备及其光催化性

采用空气-水界面自组装法制备TiO2纳米粒子,将其放入AgNO3溶液中浸泡,后在较低温度下进行热处理(400℃),获得Ag-TiO2复合纳米颗粒.利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、紫外可见光谱(UV-vis)等分析测试手段进行表征.结果表明:复合粒子可以显著提高TiO2颗粒光催化活性.以甲基橙为模拟污染物,经过光催化试验,证实复合纳米粒子具有较好的光催化活性,降解率达到96.25％.     

原子层沉积制备二氧化钛薄膜及其光催化性能

采用原子层沉积方法在K9玻璃上制备出TiO2薄膜,利用XRD、SEM、AFM、分光光度计和紫外-可见光谱仪表征了不同沉积温度下薄膜的物相结构、光学性能和光催化性能.结果 表明:25和120℃下制备的TiO2薄膜为无定形态结构,210和300℃下可获得锐钛矿结构;随着沉积温度的升高,薄膜的晶粒尺寸变大,表面粗糙度增加,透...     

载体对二氧化钛光催化降解苯的影响

研究了以活性炭、沸石、膨润土和硅藻土为负载的TiO2对空气中苯的光催化降解性能，并与无负载的TiO2进行了比较，结果表明，选择合适的载体可以起到吸附与催化氧化的协同作用，提高催化效率。     

原子层沉积制备二氧化钛薄膜及其光催化性能研究

采用原子层沉积方法在K9玻璃上制备出TiO₂薄膜,利用XRD、SEM、AFM、分光光度计和紫外-可见光谱仪表征了不同沉积温度下薄膜的物相结构、光学性能和光催化性能。结果表明：25℃和120℃下制备的TiO₂薄膜为无定形态结构,210℃和300℃下可获得锐钛矿结构;随着沉积温度的升高,薄膜的晶粒尺寸变大,表面粗糙度增加,透射率降低,光催化性能增强;300℃下制备的TiO₂薄膜(2mm*2mm)经过12h的紫外可见光照射,甲基橙溶液的降解率可达47.16%,通过增加样品表面积可明显提高对甲基橙溶液的降解率。     

纳米二氧化钛光催化活性影响因素的研究

以苯酚为模拟污染物，考察了不同晶型、溶液初始pH值、反应物初始浓度、氧气的协同作用对TiO2悬浮体系光催化活性的影响；并将TiO2负载到活性炭纤维上，制备了固定体系的TiOJACF复合催化剂。结果表明，具有混晶结构的P25降解速率比纯锐钛矿TiO2快；溶液pH=6及苯酚初始浓度为150mg／L时，降解速度最快；通入氧气，可以提高催化剂活性；光催化降解苯酚表明，TiO2/ACF复合催化剂具有较好的光催化活性。     

—种制备复合二氧化钛光催化材料的方法

涉及制备复合二氧化钛光催化材料的方法。采用溶胶-凝胶法利用钛盐制备锐钛矿型TiO2前驱体，在前驱体中添加钨盐和钒盐，对混合物进行焙烧得WO3-V2O5/TIO2复合光催化材料。本发明是采用溶胶-凝胶法和简单焙烧结合的一种新颖的制备纳米粉体方法，技术相对简单，操作容易，对设备要求低，故能较大降低成本。     

掺铜二氧化钛纳米颗粒的制备及其催化性能（英文）

采用溶胶-凝胶法制备掺铜量为0~2.0%(摩尔分数)的二氧化钛纳米颗粒。应用X射线衍射(XRD)、X射线光电子能谱(XPS)和场发射电子显微镜(FE-SEM)技术对二氧化钛纳米颗粒的晶体结构、化学价态和形貌进行表征。样品的光学吸收性能用紫外-可见吸收光谱进行表征;其光催化性能通过在紫外-可见光照射下分解20 mg/L甲基橙溶液进行表征。结果表明,掺铜二氧化钛纳米颗粒具有比纯二氧化钛更优的光催化性能,尤其是铜掺杂量为1.0%的二氧化钛TiO2纳米颗粒具有最好的光催化性能。铜掺杂能提高二氧化钛在紫外-可见光区对光的吸收、减小电子-空穴对的复合,因此,铜掺杂使二氧化钛的光催化性能得到提高。     

光催化二氧化钛薄膜的制备工艺研究进展

评述了制备二氧化钛薄膜的液相法、气相法和电化学法3大类方法的优缺点，以及3大类方法所包含的溶胶-凝胶、微乳液、磁控溅射、物理气相沉积、化学气相沉积、阳极氧化和微弧氧化等方法制备二氧化钛薄膜的工艺步骤、特点及研究进展。文章最后指出，液相法由于自身存在的优点，仍将是今后二氧化钛薄膜制备和研究的重点；而光催化性能更好的掺杂二氧化钛，其研究重点是探讨掺杂方式、制备方法和优化配比等。     

TiO_2/石墨烯-Fe_3O_4磁性三元复合光催化剂的制备及光催化性能

以改进的Hummers法制备的氧化石墨烯为原料,采用共沉淀法获得磁性的石墨烯-Fe_3O_4载体,进而采用水热法制备出TiO_2/石墨烯-Fe_3O_4磁性三元复合光催化剂。借助X射线衍射(XRD)、扫描电子显微镜(SEM)及固体紫外-可见漫反射光谱(UV-vis DRS)对产物进行表征,并通过在紫外光和可见光下对亚甲基蓝的降解来评价复合光催化剂的催化性能及稳定性能。结果表明,Ti O_2/石墨烯-Fe_3O_4磁性三元复合光催化剂对亚甲基蓝的光催化降解符合拟一级动力学模型。该复合催化剂在紫外光和可见光下均具有较好的光催化性能,且催化活性均高于纯Ti O_2。石墨烯由于担当了载体和电子受体,增强了Ti O_2在可见光区域的吸收,能有效提高对目标污染物的光催化降解活性,同时通过添加磁性Fe_3O_4,进一步提高了其回收再利用性。     

Fe(Ⅲ)改性膨润土光催化降解水溶液中的4-氯苯酚

以Fe（Ⅲ）离子交换改性膨润土,制得一种多相Fenton催化剂;以4-氯苯酚为模型污染物,研究不同反应条件的影响。结果表明,复合催化剂主要含SiO2及α-Fe2O3两种晶型,Fe是以高催化活性的α-Fe2O3形式存在。复合催化剂在H2O2及紫外光的协同作用下,经60 min反应后对4-氯苯酚的降解率约100%,TOC去除率约70%,且其循环使用性能较好。在实际操作过程中,控制溶液体系的pH值为6以及H2O2与4-氯苯酚浓度比约15较为适宜;在4-氯苯酚的降解过程中,C—Cl键持续断裂,Cl-被释放出来,降解过程生成了一些不含氯的中间产物。     

硅胶负载掺钕TiO2的制备及其光催化性能

采用溶胶-凝胶法将掺钕二氧化钛负载在二氧化硅上制备复合光催化剂（Nd/TiO2-SiO2）,利用XRD、SEM、FT-IR和DRS对Nd/TiO2-SiO2进行表征,并通过甲基橙溶液的光催化降解评价其光催化性能。结果表明：Nd/TiO2-SiO2在可见光区388-619nm范围内的光吸收性能随着钕掺杂量的增大而增强,钕掺杂有利于降低电子-空穴的复合率,钕和二氧化硅提高TiO2的光催化活性。在600℃煅烧的0.1%Nd/TiO2-SiO2的光催化活性最高,1h后甲基橙降解率为82.9%。     

Preparation of nitrogen-doped titania and its photocatalytic activity

Yellowish nitrogen-doped titania was produced through sol-gel method in mild condition, with the elemental ni- trogen derived from aqua ammonia. The titania catalysts were characterized using XRD, BET, TEM, XPS, and UV-Vis diffuse reflectance spectrophotometer, and their photocatalytic activities were evaluated under UV and visible light, respec- tively. The XRD results showed that all titania catalysts were anatase. More significantly, the crystallite size of nitro- gen-doped titania increased with an increase in N/Ti proportion, and the doping of nitrogen could extend the absorption shoulder into the visible-light region, thus it possessed a higher visible-light activity illustrated by decolorization of methyl orange (65.3%) under the irradiation of visible light, whereas pure titania showed little of such kind of visible light activity. The UV-light activity of nitrogen-doped titania catalysts was worse than that of pure titania and Degussa P25. In the range of N/Ti proportion of 4-10 mol%, the activity of nitrogen-doped titania weakened appreciably in the visible-light region as the N/Ti proportion increased, whereas a reverse relationship existed under the irradiation of UV light.     

液相球磨法由氧化铋制备次碳酸铋的动力学

为解决传统次碳酸铋生产过程中成本高和环境污染问题,提出采用液相球磨法由氧化铋制备次碳酸铋的新工艺,研究用碳酸氢氨和氧化铋制备次碳酸铋反应过程的动力学,考察反应温度、氧化铋粒度、液固比以及碳酸氢氨浓度对氧化铋转化率的影响。结果表明,在9-30°C的范围内,升高反应温度、减小氧化铋粉末的粒度、扩大液固比以及提高碳酸氢氨浓度均有利于氧化铋转化率的提高。对反应产物的表征分析表明,产品的纯度较高、杂质少;SEM结果显示产品次碳酸铋主要呈针棒状形态。反应过程受产物层的扩散控制,可用未反应收缩核模型描述,反应的表观活化能为9.783 kJ/mol,同时获得了描述反应过程的半经验动力学方程。     

Preparation and characterization of platinum doped porous titania nanoparticles for photocatalytic oxidation of carbon monoxide

TiO₂ samples doped with platinum oxide were obtained by using a sol-gel low temperature approach. The photocatalytic oxidation of CO in the presence of O₂ was monitored to study the influence of the Pt doping on the photocatalytic degradation performance of TiO₂. The obtained results were compared with those obtained with TiO₂ Degussa (P-25). Photocatalytic studies of the prepared mesoporous Pt/TiO₂ nanoparticles for the photooxidation of CO revealed notable photocatalytic activity, which was 3 times higher than that of Pt photodeposited onto commercial TiO₂ Degussa P-25. Also quantum yield for CO₂ formation for mesoporous Pt/TiO₂ calcined at 500 °C is higher than that of Pt photodeposited onto commercial TiO₂ Degussa P-25 by about three times. The structure and textural properties Pt/TiO₂ were studied by X-ray powder diffraction (XRD), N₂ adsorption (BET), Transmission electron microscopy (TEM) and UV.     

Preparation and photocatalytic activity of PANI/TiO2 composite film

1. Introduction As an advanced oxidation technique (AOT), photocatalytic oxidation of semiconductor nanopar-ticles has been widely investigated by several groups during the past two decades [1-2]. Among all types of oxide semiconductor photocatalysts, nano-TiO2 is a very important photocatalyst for its strong oxidiz-ing power, nontoxicity, and long-term photostability [3]. Some researchers have reviewed the photocata-lytic mechanism of nano-TiO2 [4-5]. Generally, when the surface of TiO2 i…     

纳米TiO2的燃烧合成及其光催化性能

以TiOSO4为原料,加入燃烧剂,采用燃烧合成法制备了纳米TiO2;考察了燃烧剂的种类、燃烧剂的加入量、pH值、点火温度、煅烧时间等对产物的影响;以甲基橙溶液为实验对象,研究了该TiO2的光催化性能.结果表明:以柠檬酸为燃烧剂,当TiO(NO3)2和柠檬酸的摩尔比为9:15,溶液pH＞5,点火温度为550℃时合成TiO2.XRD测试表明,合成产物为单一锐钛矿型,晶体粒度为14.8 nm;TEM测试表明,产品粒度分布均匀;当用高压汞灯照射2 h时,甲基橙的降解率为91%.     

Preparation and photocatalytic activity of immobilized composite photocatalyst (titania nanoparticle/activated carbon)

An immobilized composite photocatalyst, titania (TiO₂) nanoparticle/activated carbon (AC), was prepared and its photocatalytic activity on the degradation of textile dyes was tested. AC was prepared using Canola hull. Basic Red 18 (BR18) and Basic Red 46 (BR46) were used as model dyes. Fourier transform infrared (FTIR), wavelength dispersive X-ray spectroscopy (WDX), scanning electron microscopy (SEM), UV-vis spectrophotometry, chemical oxygen demand (COD) and ion chromatography (IC) analyses were employed. The effects of reaction parameters such as weight percent (wt.%) of activated carbon, pH, dye concentration and anions (NO₃⁻, Cl⁻, SO₄²⁻, HCO₃⁻ and CO₃²⁻) were investigated on dye degradation. Data showed that dyes were decolorized and degraded using novel immobilized composite photocatalyst. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates where, they were further oxidized slowly to CO₂. Nitrate, chloride and sulfate anions were detected as the photocatalytic mineralization products of dyes. Results show that novel immobilized composite photocatalyst with 2 wt.% of AC is the most effective novel immobilized composite photocatalyst to degrade of textile dyes.     

Fe3+,Ce3+共掺杂纳米TiO2的相变及其降解水中CHCl3的催化性能

制备一系列Fe3 ,Ce3 共掺杂的纳米TiO2,并用X射线衍射仪进行表征。与单一金属离子掺杂相比,当x(Fe3 )=0.020和x(Ce3 )≈0.010时,Fe3 ,Ce3 共掺杂不仅显著抑制纳米晶TiO2的相转化,而且大大提高了其热稳定性。在紫外灯辐照下,用Fe3 ,Ce3 共掺杂的纳米晶TiO2可降解水中的三氯甲烷,表现出强的催化活性。随着掺杂Fe3 的摩尔分数增大,x(Fe3 )=0.020时,CHCl3的降解率存在一个最佳值,而随着掺杂Ce3 的摩尔分数增大,CHCl3的降解率先是急剧上升,而x(Ce3 )>0.020时,其增势趋缓。     

Facile synthesis of tin oxide nanocrystals and their photocatalytic activity

Tin oxide nanocrystals with diameters smaller than 10 nm were synthesized using Na₂SnO₃ and CO₂ as reactants and cetyltrimethylammonium bromide (CTAB) as stabilizer under mild conditions. As a mild acidic gas, CO₂ is favorable for the accurate adjustment of pH value of Na₂SnO₃ solution. Stannate salt is stable, cheap and easy in operation. The effects of Na₂SnO₃ concentration, CTAB concentration, aging temperature, and aging time on the nanocrystals were studied. It was found that, with the increasing Na₂SnO₃ concentration, aging temperature and aging time, SnO₂ nanocrystals size decreases. The formation of SnO₂ nanocrystals can be interpreted by electrostatic-interaction mechanism. SnO₂ nanocrystals show high photocatalytic activities in the degradation of Rhodamine B solution. The catalytic activity of small nanocrystals is higher than that of large ones.     

钛合金表面GO/纳米ZnO复合涂层的制备及性能

为了有效解决生物医用钛合金长期植入人体后,易发生细菌感染和面临有害金属离子释放的问题,采用水热反应和涂覆方法,分别在聚多巴胺(PDA)预处理的Ti6Al4V合金表面制备了氧化石墨烯涂层(GP/T)和氧化石墨烯/纳米氧化锌复合涂层(GZP/T)。系统分析了2种涂层的物相结构、微观形貌及其在林格氏液中的耐腐蚀性能和在大肠杆菌环境中的抗菌性能。结果表明:聚多巴胺发挥“双面胶”桥接作用,有效增强了涂层与基底间的化学键合;GP/T涂层抗菌率随着GO浓度增大而增大;GZP/T纳米复合涂层相较Ti6Al4V基材具有优异的耐蚀性,该复合涂层中ZnO起主要抗菌作用。