锌离子掺杂的二氧化钛介孔空心微球的制备及光催化性能

以二氧化硅为模板,钛酸四丁酯（TBOT）为钛源,硝酸锌为锌源,采用溶胶凝胶法制备了锌离子掺杂的介孔二氧化钛空心微球。采用X射线衍射（XRD）、比表面积（BET）、透射电镜（TEM）、扫描电镜（SEM）和X射线光电子能谱（XPS）等技术对样品进行表征,以亚甲基蓝（MB）的光催化降解为目标反应评价其光催化活性。结果表明,去核之后的复合微球为空心微球,壁厚为20nm左右。钛酸四丁酯溶液的滴加时间对微球的形貌影响较大,当滴加时间大于15min时,可以得到结构清晰的空心微球。用氢氧化钠溶液去除二氧化硅核,反应90min,二氧化硅可以被完全去除。X射线衍射表明,实验得到的掺杂锌离子的空心微球和没有掺杂锌离子的空心微球都是锐钛矿。当锌离子的摩尔分数为0.3%时,二氧化钛空心微球的晶粒尺寸最小,比表面积最大,催化亚甲基蓝降解的效率最高。     

铈掺杂TiO_2多孔材料的制备及光催化性能

本文以钛酸四丁酯(TBOT)为钛源、六水硝酸铈为铈源、非离子表面活性剂辛基酚聚氧乙烯醚(OP乳化剂)为模板剂采用模板法制备了锐钛矿相TiO_2多孔材料.利用X射线衍射(XRD)和扫描电子显微镜(SEM)等手段对所制备样品进行表征.以亚甲基蓝(MB)为目标降解物,研究了其光催化性能.结果表明,所制得的Ce掺杂的TiO_2多孔材料具有锐钛矿骨架,且当Ce掺杂量为0.01%,煅烧温度为500℃时制备的样品在光催化降解60min后,降解率达到了90.53%.     

介孔二氧化钛的制备及铜（Ⅱ）对其光催化氧化活性的影响

采用十六烷基三甲基溴化铵为模板剂,钛酸正四丁酯为原料,水热法合成出孔径为4.4 nm介孔二氧化钛.通过X射线粉末衍射仪、透射电子显微镜和氮气吸附技术对样品进行了表征.以甲基橙为模型化合物,考察了铜(Ⅱ)对介孔二氧化钛光催化活性的影响,研究表明:介孔二氧化钛的光催化活性与P25纳米二氧化钛相当,铜(Ⅱ)的加入提高了介孔二氧化钛的光催化活性,甲基橙的光催化降解速率与光强度成正比.     

空心微球表面定向生长TiO2纳米棒及其光催化性能研究

通过表面溶胶-凝胶处理和水热反应成功制备出包覆有二氧化钛纳米棒的复合空心微球. 用扫描电子显微镜(SEM)和X射线衍射仪(XRD)等表征了所得产品, 探索了水热反应时间、煅烧时间对产物形貌和结构的调控作用, 并对产物光催化降解亚甲基蓝进行了研究. 结果表明, 所制备的表面包覆有二氧化钛纳米棒的复合空心微球在紫外光照射下可将亚甲基蓝完全降解. 该材料质轻, 可浮于水面, 有望成为一种新型光催化剂, 应用于治理水体表面的大面积污染.     

空心锌铬铁氧体/二氧化钛复合物的制备及去污性能

以葡萄糖溶液为原料,通过水热法制备了分散性良好的碳微球;以碳微球为模板,应用化学沉淀法和热处理技术除去碳核获得空心铬锌铁氧体;用钛酸四丁酯作为钛源,在空心铁氧体表面包覆二氧化钛制备了锌铬铁氧体/二氧化钛二元复合物.采用现代分析技术表征了制备样品的微观结构、形貌和电磁性能,并对其吸附和降解染料废水的性能进行了研究.结果表明,Zn Cr_(0.25)Fe_(1.75)O_4对染料废水具有较好的去污效果,对甲基橙和罗丹明B的去污效率分别为87%和83%;TiO_2对铁氧体的包覆能提高复合物对染料废水的光催化降解性能,其中m_(T/ZCF)=0.3的ZnCr_(0.25)Fe_(1.75)O_4/TiO_2复合物的去污效果最佳,几乎与纯二氧化钛相仿.     

溶剂热法制备Ag/TiO_2纳米材料及其光催化性能

以乙醇为溶剂,钛酸四丁酯为前驱体,用溶剂热法制备了Ag表面修饰的负载型纳米二氧化钛光催化剂.利用X射线衍射(XRD)、N2吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外-可见(UV-Vis)光谱等技术对其进行了系统的表征,以亚甲基蓝(MB)溶液的脱色降解为模型反应,考察了不同Ag含量样品的光催化性能.结果表明:用溶剂热法制备的样品中TiO2皆为锐钛矿相,金属Ag颗粒沉积在TiO2表面,粒径为2nm左右,比表面积较溶胶凝胶法制备的样品大大增加,最高可达151.44m2·g-1;UV-Vis光谱和光催化实验表明:Ag修饰使TiO2对光的吸收能力大大增强,吸收带边红移至可见光区,亚甲基蓝在该复合材料上的光催化降解反应遵循一级反应动力学模型;溶剂热法制备样品的光催化性能明显好于溶胶凝胶法制备的样品,在紫外光和可见光下,Ag摩尔分数为5%的样品表现出最佳的光催化活性.     

铬和硫共掺杂二氧化钛催化剂的制备及其可见光催化性能

以钛酸四丁酯为前驱体,硝酸铬和硫脲为掺杂离子给体,通过溶胶-凝胶法成功制备了纯TiO2、不同浓度的铬掺杂和铬/硫共掺杂TiO2光催化剂.以靛红为目标污染物,进行了可见光催化降解活性测试实验.结果表明,共掺杂催化剂的活性高于未掺杂和单掺杂催化剂.当共掺杂催化剂含0.60%(原子比)的铬,1.2%(原子比)的硫,焙烧温度为500℃时具有最高的光催化降解活性.X射线衍射、N2吸附、X射线光电子能谱和紫外-可见漫反射吸收光谱表征结果显示,共掺杂催化剂为锐钛矿型,具有较高的比表面积,对可见光有较强的吸收能力.共掺杂TiO2具备较高可见光催化活性的原因可能是铬掺杂降低了TiO2的禁带宽度,拓展了可见光吸收区域,而硫掺杂能够维持体系的电荷平衡,增强催化剂对可见光的吸收.     

硫掺杂钛酸(盐)纳米管的表征与可见光光催化活性

以二硫化钛为钛源和硫源,通过与NaOH水热反应成功制备了硫掺杂钛酸(盐)纳米管。 采用X射线衍射、高分辨透射电子显微镜、扫描电子显微镜、扩展X射线吸收精细结构(EXAFS)和X光微区分析等手段对所制备的硫掺杂钛酸(盐)纳米管的结构、形貌、硫掺杂状态和掺杂量进行了表征,并以可见光光催化氧化乙醇反应为探针,采用原位气相色谱技术研究了硫掺杂钛酸纳米管的可见光光催化活性;结果表明,S原子以S2-形式取代了钛酸纳米管骨架中O原子的位置, 有效实现了硫掺杂;硫掺杂钛酸(盐)纳米管壁厚平均尺寸为2.9 nm,管径平均尺寸为9.7 nm。 可见光光催化氧化乙醇反应结果表明,掺硫钛酸纳米管在极低的掺硫量条件下,表现出比未掺杂的二氧化钛纳米管具有更高的可见光光催化活性。     

Si掺杂介孔SO2-4/TiO2的非模板剂法合成及表征

在不使用模板剂的条件下,以工业硫酸氧钛溶液为原料合成介孔偏钛酸前驱体,再经正硅酸乙酯浸渍焙烧制备了具有良好热稳定性的Si掺杂介孔SO2-4/TiO2.采用X射线衍射、N2吸附-脱附、扫描电镜、X射线能谱和傅里叶变换红外光谱等表征方法对样品的组成和结构进行了分析,并考察了该材料在亚甲基蓝氧化降解反应中的光催化性能.结果表明,在焙烧过程中,被吸附在偏钛酸孔道内的正硅酸乙酯发生水解,并与偏钛酸孔壁上的自由羟基形成 Ti - O - Si 键;Si进入二氧化钛骨架中,对孔结构起到了支撑作用,从而提高了介孔SO2-4/TiO2的热稳定性.700 ℃焙烧 2 h 后,Si掺杂介孔SO2-4/TiO2材料的比表面积仍达到189 m2/g,平均孔径为2.8 nm.400 ℃焙烧的样品在亚甲基蓝降解反应中表现出较好的光催化活性.     

一步火焰辅助热解法制备Fe掺杂嵌碳TiO2及其光催化性能

以钛酸四丁酯、无水乙醇和无水氯化铁为前驱体,通过一步火焰辅助热解法制备了Fe掺杂嵌碳TiO₂,并研究了样品的光催化活性. 利用扫描电子显微镜及能谱、X射线光电子能谱、X射线粉末衍射和紫外-可见漫反射吸收光谱等对样品的形貌、组分、晶型和光吸收进行了表征,并研究了样品在紫外和可见光下的光催化活性. 结果表明,无需后续热处理可直接得到主要是锐钛矿相TiO₂的样品,Fe³⁺以替位掺杂形式进入TiO₂晶格,随掺杂量增加,样品在可见光区域的吸光度提高,吸收带边红移. Fe掺杂量（摩尔分数）小于0.2%可改善样品的光催化活性,当Fe掺杂量为0.1%时,样品在可见光和紫外-可见光照射下均显示出最高的降解亚甲基蓝速率.     

Sonochemical fabrication of fluorinated mesoporous titanium dioxide microspheres

A sonochemical-hydrothermal method for preparing fluorinated mesoporous TiO₂ microspheres was developed. Formation of mesoporous TiO₂ and doping of fluorine was achieved by sonication and then hydrothermal treatment of a solution containing titanium isopropoxide, template, and sodium fluoride. The as-synthesized TiO₂ microspheres were characterized by X-ray diffraction (XRD), Fourier translation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, photoluminescence spectroscopy (PL), and BET surface areas. The P123 template was removed completely during the hydrothermal and washing steps, which was different from the conventional calcination treatment. The as- synthesized TiO₂ microspheres had good crystallinity and high stability. Results from the photocatalytic degradation of methylene blue (MB) showed that fluorination could remarkably improve the photocatalytic activity of titanium dioxide.     

可见光响应的铁掺杂TiO_2中空微球的制备及其光催化性能

以聚苯乙烯微球作为模板,水溶性过氧化钛配合物作为前驱体一步合成了掺铁TiO2中空微球,并利用XRD,SEM,TEM,XPS,UV-Vis等测试手段对样品进行了表征。结果表明,一步法制备的掺铁TiO2中空微球以锐钛矿相存在且具有良好的中空结构,掺杂少量铁到体系中,改变了其电子结构,使其吸收波长拓展到可见光区。光催化降解亚甲基蓝溶液的结果表明,掺杂0.75%铁的TiO2中空微球表现出更好的光催化性能。对Fe3+影响光催化活性的机理进行了讨论。     

Preparation of Ce‐doped TiO2 Hollow Fibers and Their Photocatalytic Degradation Properties for Dye Compound

Cerium‐doped titanium dioxide (TiO₂) with a hollow fiber structure was successfully prepared using ammonium ceric nitrate and tetrabutyltitanate as precursors and cotton fiber as the template. The effects of cerium (Ce)‐doping on the crystallite sizes, crystal pattern, and optical property of the prepared catalysts were investigated by means of techniques such as scanning electron microscopy (SEM), X‐ray diffraction (XRD), BET surface area, and UV‐vis diffuse absorption spectroscopy. SEM observation showed that the prepared TiO₂ fibers possessed fibrous shape inherited from the cotton fiber and had a hollow structure. As confirmed by XRD and UV‐vis diffuse absorption spectroscopy examinations, Ce‐doping restrained the growth of grain size and extended the photoabsorption edge of TiO₂ hollow fiber into the visible light region. The present photocatalyst showed higher photocatalytic reactivity in photodegradation of highly concentrated methylene blue (MB) solutions than pure TiO₂ under UV and visible light, and the amount of Ce‐doped significantly affected the catalytic property. In the experiment condition, the photocatalytic activity of 0.5 mol% Ce‐doped TiO₂ fiber was optimal of all the prepared samples. In addition, the possibility of cyclic usage of the photocatalyst was also confirmed. The material was easily removed by centrifugal separation. Therefore, using the template method and by doping with cerium, TiO₂ may hopefully become a low‐energy consuming, high activity and green environmentally friendly catalytic material.     

Nanosized TiO<Subscript>2</Subscript> particles decorated on SiO<Subscript>2</Subscript> spheres (TiO<Subscript>2</Subscript>/SiO<Subscript>2</Subscript>): synthesis and photocatalytic activities

Nanosized TiO₂ and nano-anatase TiO₂ decorated on SiO₂ spherical core shells were synthesized by using a sol–gel method. The synthesized pure TiO₂ nano particle and TiO₂ grafted on SiO₂ sphere with various ratios have been characterized for their structure and morphologies by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrophotometry (FTIR) and transmission electron microscopy (TEM). Their surface areas were measured using the BET method. The photocatalytic activity of all nanocomposites was investigated using methylene blue as a model pollutant. The synthesized TiO₂/SiO₂ particles appeared to be more efficient in the degradation of methylene blue pollutant, as compared to pure TiO₂ particles.     

Preparation of Anatase Hollow TiO2 Spheres and Their Photocatalytic Activity in the Photodegradation of Chlorpyrifos

Hollow anatase titania (TiO₂) spheres were synthesized using fructose and tetrabutyl titanate (Ti(OC₄H₉)₄, TBT) as the precursors via the conventional hard template method. The morphological, structural and thermal properties of the products were characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG‐DTA), Brunauer? Emmett? Teller (BET) surface area analysis and diffuse reflectance ultraviolet visible (DR UV? Vis) spectroscopy. XRD revealed that the hollow TiO₂ prepared was in the anatase phase and the BET surface area measured was about 22 m² g^?1. The photocatalytic activity of the synthesized hollow anatase TiO₂ in the photodecomposition of chlorpyrifos was 18.67 % higher than that obtained using commercial TiO₂.     

简易模板剂法制备多级介孔TiO2微球及其在染料敏化太阳能电池中的性能

采用模板剂法一步合成分级结构的介孔TiO₂微球, 考察了烷基胺类模板剂中烷基链长度对介孔TiO₂微球合成及性能影响. 将其应用于染料敏化太阳能电池的光阳极半导体薄膜中, 得到了9.5%-10.1%的高能量转换效率. X射线衍射(XRD)、物理吸附仪(BET)、扫描电镜(SEM)等的分析结果表明: 分级结构介孔TiO₂微球的晶相为纯锐钛矿型; 介孔TiO₂微球表面粗糙, 的纳米粒子堆积形成, 使微球具有介孔性质和较适宜的比表面积. 介孔TiO₂微球堆积形成了利于物质扩散的通道并具有良好的光散射效果; 同时微球介孔粗糙表面保证了染料的大量吸附, 从而提高了电池的光电流. 通过电化学阻抗分析结果验证了分等级结构介孔TiO₂微球光阳极有利于电解液的传输和物质扩散的优异性能.     

Microstructure of SiO<Subscript>2</Subscript>/TiO<Subscript>2</Subscript> hybrid electrospun nanofibers and their application in dye degradation

SiO₂/TiO₂ hybrid nanofibers were prepared by electrospinning and applied for photocatalytic degradation of methylene blue (MB). The phase structure, specific surface area, and surface morphologies of the SiO₂/TiO₂ hybrid nanofibers were characterized through thermogravimetry (TG), X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), etc. XRD measurements indicated that doping of silica into TiO₂ nanofibers can delay the phase transition from anatase to rutile and decrease the grain size. SEM and BET characterization proved that silica doping can remarkably enhance the porosity of the SiO₂/TiO₂ hybrid nanofibers. The MB adsorption capacity and photocatalytic activity of the SiO₂/TiO₂ hybrid nanofibers were distinguished experimentally. It was found that, although increased silica doping content could enhance the MB adsorption capacity, the intrinsic photocatalytic activity gradually dropped. The SiO₂ (10 %)/TiO₂ composite nanofibers exhibited the highest MB degradation rate, being superior to SiO₂ (20 %)/TiO₂ or pure TiO₂.     

Preparation of CuO/SiO<Subscript>2</Subscript> Hollow Spheres for Catalytic Oxidation of Phenol

Porous CuO/SiO₂ hollow microspheres were synthesized via an impregnation method using pure SiO₂ hollow microspheres as the supporter, and Cu species as the functional material. The hollow microspheres were characterized by X-ray diffraction, BET surface area, temperature-programmed reduction, transmission electron microscopy, and scanning electron microscopy. The catalytic activities of the CuO/SiO₂ hollow microspheres were investigated via the removal of the total chemical oxygen demand (COD) in the oxidation of phenol solution with air as an oxidant. The influence of various reaction parameters such as the reaction temperature, the partial pressure of O₂, and the initial pH of the solution were studied in detail. The coordination, dispersion and aggregation degree of copper species on porous materials play an important role for the COD removal of the phenol aqueous solution.     

Rapid Synthesis of Mesoporous TiO2 for the Photoanodes in Dye Sensitized Solar Cells

Mesoporous TiO₂ microspheres with high specific surface areas were synthesized by means of a facile one‐step microwave hydrothermal process without using any template. The mesoporous materials were rapidly achieved using TiCl₄, urea and ammonium sulphate at comparatively low microwave power (400 W) for 8 min irradiation. The morphology and microstructure of the as‐prepared products were characterized by field emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer‐Emmett‐Teller (BET) surface area analysis. Structural characterization indicates that the TiO₂ microspheres display mesoporous structure. The average pore sizes and BET surface areas of the spheres were 5.3 nm and 222 m²g^?1, respectively. The mesoporous nanocrystals synthesized at 160 °C for 8 min were then used to prepare the photoanode for dye sensitized solar cells (DSSCs). A high power conversion efficiency of 5.72% was achieved from the mesoporous TiO₂ based photoanode, representing about 25.7% improvement over the efficiency of P25 photoanode.