铁掺杂二氧化钛纳米棒阵列光催化降解甲基橙

采用水热合成法在导电玻璃衬底上制备铁掺杂二氧化钛纳米棒阵列,研究了铁掺杂量和钛酸丁酯用量对二氧化钛纳米棒阵列光催化性能的影响,采用SEM和XRD分析了铁掺杂二氧化钛纳米棒阵列的形貌和结构,结果表明,铁掺杂量为9%,钛酸丁酯用量为1.6%时可以获得尺寸较细、均匀有序排列的二氧化钛纳米棒阵列,具有金红石型结构,甲基橙降解率可达34.15%。     

水热反应合成Fe掺杂TiO_2纳米棒阵列

利用水热合成法,在导电玻璃衬底上制备铁掺杂二氧化钛纳米棒阵列。采用电子扫描显微镜(SEM)和X-射线衍射仪(XRD)研究了铁含量对二氧化钛纳米棒阵列形貌和结构的影响,确定了最佳铁掺杂量为9%。并测试了不同光照时间下铁掺杂二氧化钛纳米棒阵列的光催化性能,当光照时间2 h时,甲基橙降解率可达34.15%。     

铁酸锌掺杂TiO2的制备及光催化性能研究

以钛酸丁酯和自制铁酸锌为原料,用溶胶-凝胶法制备了未掺杂的纳米TiO2和掺杂的ZnFe2O4-TiO2纳米粉体,利用SEM和XRD对产物的晶型、晶貌及晶粒大小进行表征,并通过对甲基橙的光催化降解研究了掺杂铁酸锌对纳米TiO2光催化活性的影响。结果表明:在500℃煅烧得到的纳米粉体光催化活性较高,催化剂的用量为1.0g/L时,其催化效果最好,对甲基橙的降解率分别为95%和96%。     

Fe^3＋掺杂纳米TiO2光催化剂的制备及其光催化性能研究

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,正丁醇为助表面活性剂,环己烷为油相,采用微乳液法制备出Fe3+掺杂纳米TiO2,用X-射线衍射(XRD)对纳米TiO2粒径、物相等方面进行了表征.通过光催化降解甲基橙溶液考察了TiO2的光催化性能.甲基橙降解实验结果表明,溶液的pH=2时降解率可达100%;掺杂Fe3+会影响TiO2光催化性能,n(Ti4+):n(Fe3+)=1:0.000 4的TiO2在前10 min降解率高达54.50%,60 min降解率可达93.33%,掺杂浓度增大到一定程度后,降解率反而下降,说明存在较佳掺杂浓度.另外,溶液初始浓度对TiO2光催化性能有一定的影响.     

纳米Fe-ZnO晶体光催化降解染料废水

采用NAC-FAS工艺在醇水溶液中制备了纳米Fe-ZnO晶体,利用XRD、SEM和UV-Vis等方法对样品的结构及光学性能进行了表征。结果表明,随着Fe掺杂比例的增加Fe-ZnO的光催化活性增加,当Fe掺杂比例为9%时的纳米Fe-ZnO晶体光催化活性最优。双氧水和纳米Fe-ZnO晶体协同作用下可以增加对甲基橙的降解率,纳米Fe-ZnO晶体的质量浓度为10 g/L时对甲基橙的降解率最佳。     

纳米Fe-ZnO晶体光催化降解染料废水

采用NAC-FAS工艺在醇水溶液中制备了纳米Fe-ZnO晶体,利用XRD、SEM和UV-Vis等方法对样品的结构及光学性能进行了表征。结果表明,随着Fe掺杂比例的增加Fe-ZnO的光催化活性增加,当Fe掺杂比例为9%时的纳米Fe-ZnO晶体光催化活性最优。双氧水和纳米Fe-ZnO晶体协同作用下可以增加对甲基橙的降解率,纳米Fe-ZnO晶体的质量浓度为10 g/L时对甲基橙的降解率最佳。     

钆掺杂纳米二氧化钛光催化剂的制备及其光催化性能研究

以钛酸四正丁酯为原料,采用溶胶-凝胶法制备不同Gd3+掺杂量的纳米TiO2光催化剂,用500 W长弧氙灯模拟太阳光,并以甲基橙模拟水研究样品的光催化性能。结果表明,钆掺杂并没有改变纳米二氧化钛的晶型结构,微观形貌为球状颗粒,粒径约为30 nm;当掺杂摩尔分数为1.26%时,光催化性能最好,用量为1 g/L,反应2 h时,降解率达51%。     

钆掺杂纳米二氧化钛光催化剂的制备及其光催化性能研究

以钛酸四正丁酯为原料,采用溶胶-凝胶法制备不同Gd3+掺杂量的纳米TiO2光催化剂,用500 W长弧氙灯模拟太阳光,并以甲基橙模拟水研究样品的光催化性能。结果表明,钆掺杂并没有改变纳米二氧化钛的晶型结构,微观形貌为球状颗粒,粒径约为30 nm;当掺杂摩尔分数为1.26%时,光催化性能最好,用量为1 g/L,反应2 h时,降解率达51%。     

银锌共掺杂纳米TiO2的制备及光催化性能

金属离子掺杂纳米TiO2能加强二氧化钛的光催化降解能力。用溶胶凝胶法制备了银锌共掺杂纳米TiO2,并以甲基橙光催化降解为例考察掺杂离子、掺杂量、催化剂加入量等对光催化性能的影响。     

铁掺杂氧化锌纳米晶的制备及光催化性能研究

通过水热法制备了铁掺杂氧化锌纳米晶,采用红外、X射线衍射（XRD）、可见光谱对其进行了表征,并以铁掺杂纳米氧化锌对亚甲基蓝进行催化降解实验来检验其催化降解性能,结果表明当Fe^＋／ZnO纳米晶浓度为1．0mol／L、亚甲基蓝质量浓度为5mg／L、太阳光照射3h时,甲基橙降解效果最好,降解率达90％以上。     

Nucleation and Growth of Anatase Crystallites on Cotton Fabrics at Low Temperatures

Anatase nanocrystalline titania coatings were produced on cotton fabrics from alkoxide solutions using a low-temperature sol–gel process under ambient pressure. Titania coatings of the anatase form were obtained via a classical hydrolysis and condensation reaction of titanium isopropoxide that was followed by a boiling water treatment for 180 min. Spectroscopic and microscopic characterizations of the titania thin films showed that the anatase form is predominant throughout the film after the boiling water treatment and that the size of the grains is about 20 nm. The titania coating on fabrics is a promising process for use as an antibacterial photocatalyst in the textile industry.     

Correlating Photoluminescence and Photocatalytic Activity of Mixed-phase Nanocrystalline Titania

Mixed-phase nanocrystalline titania with varying rutile-content has been synthesized via solvent mixing and calcination treatment of sol–gel derived nanocrystalline anatase and rutile precursors. The mixed-phase nanocrystalline titania has been characterized using different analytical techniques for analyzing their phase contents, nanocrystallite size distribution, band-gap, and photoluminescence. The photocatalytic activity of mixed-phase nanocrystalline titania has been studied by monitoring the degradation of methylene blue dye in an aqueous solution under ultraviolet-radiation exposure. A strong correlation between photoluminescence and photocatalytic activity has been demonstrated for the mixed-phase nanocrystalline titania.     

纳米二氧化钛的制备,表征及应用

综述了纳米二氧化钛的制备方法及结构表征的基本概况，并介绍了１０ 年来纳米二氧化钛的应用研究发展动态     

Pure and (zinc or iron) doped titania powders prepared by sol-gel and used as photocatalyst

Pure and doped (zinc and iron) nanocrystalline titania powders were prepared by the sol-gel route. Doping tends to change the existing crystalline phases and their degree of crystallinity, but particle size distribution and morphology of the particles are also affected. In the pure titania system, the main crystalline phase is anatase but rutile is also present. The doped (Zn and Fe) titania crystallizes only as anatase. The undoped titania shows a bimodal distribution of particles size: fine (20-40 nm) and coarse (300-500 nm) grains. The doped TiO₂ powder also exhibits a much more uniform particle size distribution, with all grains under 40 nm.The photocatalytic efficiency of suspended powders was tested on the decolouration of Orange II aqueous solutions under visible artificial light irradiation. The maximum decolouration reached by the pure TiO₂ was 81% at a rate of 3.6 × 10⁻³ min⁻¹. Iron doping decreases the photocatalytic activity; the maximum dye degradation was only 43% at a rate of 1.3 × 10⁻³ min⁻¹. On the contrary, the performance of Zn-doped titania was better, having a decolouration rate of 17.7 × 10⁻³ min⁻¹.     

掺镧纳米TiO2的光催化性能研究

研究了掺镧纳米TiO₂的物理特性及光催化活性，探讨了它们之间的关系，通过对甲基橙和罗丹明两种不同结构物质的降解实验，发现掺镧纳米TiO₂光催化性能具有广泛性。用于实际印染废水处理，再次验证掺镧能提高TiO₂的光催化效能，掺镧摩尔分数为0.02%时光催化效果最好。     

Synthesizing and Comparing the Photocatalytic Properties of High Surface Area Rutile and Anatase Titania Nanoparticles

Rutile titania nanocrystalline particles with high specific surface areas were directly prepared by thermal hydrolysis of titanium tetrachloride aqueous solution. The as-prepared rutile titania powder was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller surface area analysis, and Fourier transform Raman and IR spectroscopies. Neither anatase nor amorphous titania could be detected in this titania powder by XRD, Raman spectroscopy, and high-resolution TEM. In the phenol degradation reaction, the rutile titania powder with an initial crystalline size of 7 nm was found to have higher photocatalytic activity than that of anatase titania with the same specific surface area. The rutile titania powders calcined at 300° and 450°C also showed a relatively high photocatalytic property. The high activity of the as-prepared rutile titania was attributed to the abundance of hydroxy groups in the powder, as was proven by thermogravimetric analysis data, which provided more active sites for the degradation reaction.     

多孔纳米二氧化钛薄膜的制备及其光催化活性

本文采用溶胶凝胶法在普通玻璃基片上成功制备了多孔纳米二氧化钛薄膜。用扫描电镜对薄膜的表面形貌进行了表征,同时利用XRD谱图对其晶型结构进行分析,结果表明,加水量、升温速度等因素对薄膜的质量都有影响。光催化实验表明：多孔纳米二氧化钛薄膜的催化效果最好,120min内甲基橙降解率可达到98%。     

介孔TiO_2的结构分析

研究了热处理过程中介孔TiO2 的结构及晶粒尺寸、比表面积间的相互关系,为纳米结构材料的定量研究奠定了基础。借助GWShere的圆柱通孔模型,将有孔氧化物视为立方结构体,通过比表面积、孔径、密度等参数的计算,对介孔TiO2 的微结构进行了分析,结果说明其高比表面积主要来自于纳米晶和孔结构两者共同作用。并在晶粒尺寸、比表面积、孔容之间建立了定量关系模型,不仅解释了其比表面积的变化规律,也使得预测孔结构数据成为了可能。     

Thermally stable nanophase anatase titania with mesoporous texture by pseudo-inorganic templating

Thermally stable mesoporous nanocrystalline anatase titania has been prepared by a pseudo-inorganic templating method by codoping with lanthanum and silica followed by chemical leaching. The methodology uses lower temperatures that than reported previously and is applicable to the formation of both powders and coated glass surfaces.     

Photocatalytic decomposition of methylene blue using nanocrystalline anatase titania prepared by ultrasonic technique

Nanocrystalline particles of pure anatase titania were prepared by sol–gel method at ambient temperature using ultrasonication (Ti-US). The advantages of ultrasonication method are demonstrated as compared to the conventional stirring method of preparation of titania (Ti-S). The physico-chemical properties of the samples were investigated by powder XRD, SEM, TEM, low temperature (77 K) nitrogen sorption, and UV–Vis spectroscopic techniques. More uniform distribution/dispersion of the nanoparticles (SEM), marginally higher surface area, better thermal stability, and phase purity are some of the advantages of preparation of nanocrystalline titania by ultrasonication method. The UV–Vis diffuse reflectance spectra of the samples prepared by ultrasonication method were blue shifted compared to pure anatase due to decrease in particle size. The behavior of anatase titania in photocatalytic decomposition of methylene blue in aqueous medium was studied as a function of the method of preparation and the crystallite size. The nanoparticles prepared by ultrasonication method were more effective than both, the sample prepared by conventional stirring method and commercial Degussa P-25. The higher photocatalytic activity of Ti-US is attributed to the more uniform size of the particles as compared to Ti-S samples.