纳米二氧化钛的电化学合成

以二氧化钛为前驱体,用电化学合成方法制备纳米晶二氧化钛粉体,探讨了TiCl4的水解反应及在电解过程中的电极反应,试验研究了二氧化钛溶胶的制取和粉体的获得,结果表明在实验条件下可获得易于分散的纳米级二氧化钛粉体.     

以钛氧有机物为前驱物制备具有高光催化活性的纳米二氧化钛晶体

 纳米二氧化钛的制备方法及前驱物的差别影响其光催化活性．将20ml钛酸丁酯及30ml乙酐在密闭容器中与50ml环己烷混合，在70～85℃反应30min，生成微细的非晶钛氧有机物；经FT－IR和TGA分析，该物质被确认为计量式是TiOOOCCH3）2和TiO（OC4H9）（OOCCH3）的混合体．该钛氧有机物前驱物经焙烧后得到具有高光催化活性的纳米二氧化钛晶体．表征结果表明，钛氧有机物在焙烧过程中，其表面的吸附物及键合有机基团在400℃以前发生脱附和氧化分解；在389～405℃间形成锐钛矿型晶体，在600℃出现金红石晶型；600℃焙烧3h所得样品的比表面积为86m2／g，其二次粒子呈200～300nm条形体，孔隙大于20nm；单分散粒子为球形单晶，粒径为22nm；表面物理吸附水量为1．21％，加热至800℃时失重1．48％，粉体稳定纯净．光催化实验结果表明，以钛氧有机物为前驱物制备的纳米二氧化钛晶体具有高的光催化活性，光降解丁基罗丹明溶液的反应速率常数约为溶胶－凝胶法制备的催化剂样品的4倍．表面氧空缺和一定量的表面羟基可能是粉体具有高光催化活性的重要因素．     

电化学法制备高热稳定性锐钛矿型纳米TiO2

以醇中加入少量有机腕导电盐作为电解液,以工业纯钛作“牺牲”阳性,控电流电解,可分别得到乙醇钛、异丙醇钛、正丁醇然等的相应醇溶液。然后直接水解,经溶胶－凝胶（Ｓｏｌ－ｇｅｌ）过程,形成凝胶前体,在４５０℃,７２０℃煅烧３０ｍｉｎ后,均得到高热稳定锐钛矿型（ａｎａｔａｓｅ）纳米ＴｉＯ２（１０ｎｍ左右）。通过ＦＴＩＲ,ＸＲＤ,ＴＥＭ等测试手段,对钛醇盐和纳米ＴｉＯ２进行了表征。本文同时讨论了不同钛醇盐制     

二氧化钛纳米管阵列薄膜的超声辐射阳极氧化制备

通过使用铂片作为对电极在含有氢氟酸的二甲基亚砜溶液中, 将金属钛片进行阳极氧化的方法制备得到二氧化钛纳米管阵列薄膜. 在施加40 V偏压超声辐射作用下阳极氧化24 h条件下得到的二氧化钛纳米管长达到680 nm, 管内直径25 nm, 管壁厚度约3～5 nm. 采用了XRD和TEM等分析手段表征了二氧化钛纳米管阵列薄膜的微观结构和表面形貌, 分别测试了薄膜的光吸收性能、循环伏安特性和光化学转换效率, 并和碱性溶胶-凝胶方法制备的纳米晶二氧化钛薄膜作了对比研究. 实验制备的二氧化钛纳米管阵列薄膜电极的光吸收率比纳米晶二氧化钛薄膜提高了40%, 光电化学转换效率前者是后者的6倍, 实验结果表明二氧化钛纳米管阵列薄膜结构有利于加快电子的传输, 并能减少电荷复合, 采用这种二氧化钛纳米管阵列薄膜结构的染料敏化太阳能电池光电极有望进一步提高太阳能电池的效率. 本文还探讨了在超声波辐射作用下二氧化钛纳米管阵列薄膜的形成机理.     

钛醇盐电化学合成的研究

采用钛金属为“牺牲”阳极,首次在无隔膜电解槽中,电化学一步法制备了纳米TiO~2前驱体钛醇盐Ti(OEt)~4,Ti(OPr-i)~4,Ti(OBu)~4。产物通过元素分析、红外光谱(FT-IR)、拉曼光谱进行表征。电化学一步法直接制备纳米材料前驱体钛醇盐,克服了传统化学方法合成金属醇盐步骤多、产率低、纯度达不到要求及后续分离繁琐等缺点。本文同时讨论了影响电合成钛醇盐的关键因素及可能的反应机理,实验表明钛在醇溶液中呈点蚀行为,钛醇盐卤化物Ti(Ⅲ)(OR)~nBr~m在阳极形成,然后被氧化为Ti(Ⅳ)(OR)~nBr~m,这种物质在阴极上ROH参与下被还原生成钛醇盐Ti(OR)~4,钛阳极表面拉曼光谱证实了上述观点。防止阳极钝化,温度控制在50～60℃之间,彩有机胺溴化物为导电盐,可以提高电合成收率。     

纳米SnO2/TiO2电极的制备及其电催化降解间-硝基苯酚

用电化学方法在乙二醇溶液中制备锡、钛醇盐配合物Sn0.75Ti(OCH2CH2OH)(7-x),将电解液水解、干燥后在400℃煅烧2 h,得到纳米级SnO2/TiO2粉体。通过红外光谱(FT-IR)和拉曼光谱(Raman)对电解产物进行测试,纳米SnO2/TiO2粉体通过X射线粉末衍射(XRD)和扫描电子显微镜(SEM)进行表征。实验表明,在有机体系电解得到的纳米SnO2/TiO2粉体颗粒分散较理想,粒径在100～200 nm。再通过溶胶-凝胶法在钛丝表面得到纳米SnO2/TiO2电极,采用循环伏安法研究电极在酸性溶液和间-硝基苯酚溶液中的氧化还原行为和电催化活性。结果表明,纳米TiO2掺杂SnO2电极的氧化峰电流达到143×10-3A/cm2,氧化还原峰电位差明显减小,催化降解间-硝基苯酚的COD去除率达到86.1%,具有较高的电催化活性。     

直接热氧化制备氧化钛薄膜电极的研究Ⅰ. 制备、结构和电化学性质

采用原子力显微镜、 X光衍射仪、电化学阻抗谱等手段对热氧化制备氧化钛膜的结构和电化学性质进行了研究.结果表明,金属钛直接热氧化制备的薄膜为金红石型二氧化钛薄膜;随氧化温度升高和时间延长,薄膜结晶度逐渐增大;随氧化温度升高,二氧化钛平带电位向负方向移动;当温度大于600℃后,二氧化钛结晶致密,电子导电性减小.     

针形颗粒二氧化钛纳米薄膜的制备

使用醋酸修饰的溶胶-凝胶法制备了一种由针形颗粒构成的二氧化钛纳米薄膜.研究发现,可以通过控制溶胶-凝胶过程的反应条件控制所制备的纳米薄膜的形貌.对这种形貌的形成机理进行了讨论.     

不同形态二氧化钛-石墨烯复合材料的表征及光催化性能研究

研究了二氧化钛的形态对二氧化钛-石墨烯(GN)复合材料光催化性能的影响。采用水热法制备了3种不用形态的二氧化钛,即钛纳米管(TNT)、钛纳米片(TNS)与二氧化钛纳米粒子(TNP)。采用X射线衍射、傅里叶变换红外光谱、透射电子显微镜、X射线光电子能谱、紫外-可见分光光度法等对所得的复合材料进行表征。通过在紫外灯照射下降解活性黑染料与诺氟沙星药物的混合废水测试了复合材料的光催化性能。结果表明:不同形态二氧化钛-石墨烯复合材料的光催化性能均优于纯商业用二氧化钛,所制备材料在形态上的差异对复合材料催化性能也有较大的影响。     

自蔓燃工艺制备纳米TiO2降解制药废水的研究

目前已报道的制备纳米二氧化钛的方法有气相氧化法[1,2]、水热法[1,3]和溶胶-凝胶(sol-gel)法[1,4,5]等。这些方法均以有机钛盐或无机钛盐为原料,制备成本高,不利于在废水处理中作光催化剂推广使用。溶胶—凝胶自蔓燃法(简称SAS)也称低温燃烧合成法,由于工艺简单、反应条件易于     

Ultrathin functional films of titanium(IV) oxide

Chemistry and physics of thin semiconducting layers of various types are subjects of intense research. Especially when nanotechnology methods such as self-assembly are involved, amazing structural and/or functional properties may appear. Also modern physical methods using variously organized plasma arrangements are able to produce uniform structures with distinctive functionality. In this review, based virtually on our own work, discussions on the preparation, structure, morphology, and function of titanium(IV) oxide nanoscopic thin films are presented. It was shown that structurally and functionally similar titanium(IV) oxide films can be prepared via completely different preparation techniques. Function tests were arranged as “primary”, covering the assessment of the light induced charge separation efficiency, and “secondary”, based on photocatalytic surface oxidations.     

Preparation and properties of SiO2-TiO2 thin films from silicic acid and titanium tetrachloride

The preparation of SiO₂-TiO₂ thin films by the sol-gel method using silicic acid and titanium tetrachloride as starting materials was studied. The homogeneous sols were obtained by the condensation reaction of silicic acid with titanium tetrachloride in methanol-tetrahydrofuran. The dipcoating of slide glasses and silicon wafers followed by heat treatment gave oxide thin films of 88–93% transmittance, 3000–4500 Å thickness, and 1.45–1.80 refractive index, depending on heat-treatment temperature and TiO₂ content. FT-IR measurement showed that the Si-O-Ti bond is formed even in the sol and films. The variations of film thickness and refractive index on transformation from the gels into the oxides were found to be quite low.     

介孔TiO2-ZnO复合薄膜的制备与表征

以三嵌段聚合物P123为模板剂, 以钛酸异丙酯和二水乙酸锌为无机前驱体, 利用溶胶-凝胶法和旋涂法成功地制备了不同ZnO含量的介孔TiO2-ZnO复合薄膜. 在ZnO前驱体摩尔分数为0~50％范围内获得薄膜质量较高的介孔TiO2-ZnO复合薄膜. 用小角XRD、扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、能谱仪(EDS)、紫外-可见吸收光谱(UV-Vis)及X射线光电子能谱(XPS)对所得的复合薄膜进行了表征和分析. EDS和XPS等研究证明介孔薄膜为TiO2和ZnO的复合体系, 且ZnO前驱体含量的增加仍能保持TiO2-ZnO复合薄膜的均匀性. UV-Vis研究结果表明, 介孔复合薄膜的光学带隙宽度为3.45-3.58 eV, 随着ZnO含量的增加, 复合薄膜的紫外吸收蓝移.     

TiO2 nanotube, nanowire, and rhomboid-shaped particle thin films fixed on a titanium metal plate

Titanium dioxide thin films having various nanostructures could be formed by various treatments on sodium titanate nanotube thin films approximately 5 μm thick fixed on titanium metal plates. Using an aqueous solution with a lower hydrochloric acid concentration (0.01 mol/L) and a higher reaction temperature (90 °C) than those previously employed, we obtained a hydrogen titanate nanotube thin film fixed onto a titanium metal plate by H⁺ ion-exchange treatment of the sodium titanate nanotube thin film. Calcination of hydrogen titanate nanotube thin films yielded porous thin films consisting of anatase nanotubes, anatase nanowires, and anatase nanoparticles grown directly from the titanium metal plate. H⁺ ion-exchange treatment of sodium titanate nanotube thin films at 140 °C resulted in porous thin films consisting of rhomboid-shaped anatase nanoparticles.     

Detection of Cadmium and Copper Cations Using Amorphous Nitrogenated Carbon Thin Film Electrodes

Nitrogenous amorphous carbon (a‐CN_x) thin films were deposited by radio‐frequency cathodic magnetron sputtering (13.56 MHz) on polished and etched titanium disks. While these films are cheaper to prepare than commonly reported carbon‐based electrodes, the usable electrochemical window in aqueous solution is within the same range and spans from ?1.5 to +1.8 V vs. SCE. The electrochemical reactivity was tested using the ferri‐ferrocyanide redox couple as a function of the thin films preparation parameters. The obtained electrochemical properties allow the use of these a‐CN_x thin films for stripping electroanalysis of cations in water, minimizing potential solvent reactivity. Cadmium and copper were used to test these detection abilities. Better analytical properties (notably sensitivity and linearity) were obtained as compared to a commercial boron doped diamond electrode. Preliminary competition/interaction experiments for these two cations were performed.     

Surface functionalized titanium thin films: zeta-potential, protein adsorption and cell proliferation

The relationship between electric charge at a material surface and protein adsorption is essential to understand the mechanism of biological integration of materials with tissues. This study investigated the influence of titanium thin films' surface chemistry and surface electric charge (zeta-potential) properties on protein adsorption and cell proliferation. Titanium thin films were surface functionalized with different functional end groups, such as -CH=CH2, -NH2 and -COOH groups in order to produce surfaces with a variety of electric charge properties. The chemical compositions, electric charges and wettability were investigated by using X-ray photoelectron spectroscopy (XPS), zeta-potential measurements and water contact angle measurements, respectively. XPS revealed the surface functionalization of titanium films with -CH=CH2, -NH2, and -COOH groups, which were converted from -CH=CH2 groups. Ti-COOH samples showed the lowest water contact angles and zeta-potential compared to all other samples investigated in this study. NH2-terminated titanium films displayed intermediate contact angles of 70.3+/-2.5 degrees . Fibrinogen adsorption on titanium films and surface functionalized titanium films were investigated in this study. Ti-COOH samples displayed a lower protein adsorption than all other groups, such as NH2-, -CH=CH2-terminated titanium thin films. A tendency that the lower zeta-potential of the samples, the lower the protein adsorption at their surfaces was observed. In vitro cell proliferation tests were also performed on the different surface functionalized titanium films. NH2-terminated titanium films displayed good cell proliferation and cell viability tendency. However, a lower cell proliferation on COOH-terminated titanium films was observed compared with NH2-terminated titanium films. This effect was attributed to the difference in protein adsorption of these samples.     

阳极氧化TiN薄膜制备N掺杂纳米TiO2薄膜及其可见光活性

室温下通过电泳沉积(EPD)的方法在Ti片表面制备TiN薄膜, 然后对TiN薄膜进行阳极氧化得到N掺杂多孔纳米结构的TiO2薄膜. 利用X射线衍射(XRD), X射线光电子能谱(XPS), 扫描电子显微镜(SEM)及光电化学方法对得到的薄膜进行表征. XRD测试结果表明, 经过阳极氧化并在350 ℃空气气氛中退火1 h的薄膜中存在锐钛矿晶型的TiO2. XPS的结果表明, 样品中的N元素取代部分O, 且N的摩尔分数为0.95%. SEM显示, 经阳极氧化后薄膜表面出现多孔纳米结构. 光电化学测试结果显示, 阳极氧化提高了N掺杂TiO2薄膜在可见光下的光电响应. 经阳极氧化并热处理的薄膜在0 V电位及可见光照射下光电流密度为2.325 μA·cm-2, 而单纯热处理的薄膜在相同条件下光电流密度仅为0.475 μA·cm-2. 阳极氧化得到纳米多孔结构提高了N掺杂纳米TiO2薄膜的表面积, 从而对可见光的响应增大.     

TiO2-MoO3复合纳米管阵列薄膜的制备及其可见光活性

通过阳极氧化的方法制备TiO₂纳米管薄膜, 在MoO₃存在的条件下对该薄膜进行热处理得到TiO₂-MoO₃复合纳米管阵列薄膜. 利用X射线衍射(XRD), 扫描电子显微镜(SEM), X射线光电子能谱(XPS), 电化学阻抗谱(EIS), Mott-Schottky 及光电化学方法对得到的薄膜进行了表征. XRD结果表明, TiO₂-MoO₃复合纳米管薄膜中的TiO₂主要为锐钛矿晶型. SEM实验证实了薄膜纳米管结构的存在, 样品中的MoO₃均匀地分散在TiO₂纳米管表面. 利用XPS方法分析了TiO₂-MoO₃复合纳米管薄膜元素的组成, 结果表明, MoO₃在TiO₂表面形成TiO₂-MoO₃复合纳米管薄膜. 研究了热处理温度以及热处理时间对样品的光电化学性能的影响, 相对于单纯TiO₂纳米管薄膜, 适量引入MoO₃提高了样品在可见光区的光电响应能力, 样品的平带电位负移. 在450 °C热处理60 min制得的TiO₂-MoO₃复合半导体纳米管阵列薄膜光电响应活性最高.     

有序介孔氧化硅薄膜制备及其组装化学

本文综述了近年来利用有机模板法合成有序介孔二氧化硅薄膜的研究进展，重点阐述了两相界面外延生长和蒸发诱导自组装两种制备方法及其合成机理。此外，讨论了有序介孔二氧化硅薄膜的组装化学，包括金属元素掺杂，纳米粒子在介孔薄膜中的组装，以及有机物/二氧化硅纳米复合薄膜的制备，并对介孔二氧化硅薄膜未来的发展趋势做了展望。     

TixV1-xO2薄膜的光学及相变特性

采用射频磁控溅射方法,在c-Al2O3(0001)基底上制备了不同钒钛比例的TixV1-xO2(0≤x≤1)薄膜,利用X射线衍射(XRD)、拉曼(Raman)光谱、紫外-可见-近红外(UV-Vis-NIR)光谱对薄膜结构及光学性能进行测试分析,计算薄膜的太阳能智能调节率和光学带隙.实验结果及分析表明:随着Ti含量的增加,薄膜的红外调节特性和热滞特性逐渐减弱直至消失;薄膜样品的光学带隙随着Ti含量的增加而变宽,光响应范围发生蓝移;其光学带隙随着V含量的增加而变窄,光响应范围发生红移.