纳米TiO2的制备表征及光催化性能研究

采用溶胶—凝胶法制备纳米TiO2光催化剂。通过XRD、FT-IR、PL等对TiO2样品进行表征和分析,并以亚甲基蓝(MB)作为目标降解物,考察经不同热处理温度TiO2催化剂对MB的降解效果。结果表明:所制备的TiO2粉体在500℃热处理5h后为锐钛矿相与金红石相的混晶相,对亚甲基蓝(MB)降解率最高。光催化剂存在最佳热处理温度和最佳用量。     

伊利石/纳米TiO_2光催化剂的制备及其降解染料综合实验设计

基于伊利石/纳米TiO_2光催化剂的制备、光催化降解染料性能以及产物结构的表征,设计了一个综合研究性实验。该实验考察了反应体系的温度、时间及纳米TiO_2负载量对降解亚甲基蓝溶液(MB)效果的影响。运用了X-射线衍射(XRD)、X射线荧光衍射(XRF)、扫描电镜(SEM)对原料及反应产物进行了表征;利用紫外-可见分光光度计及光催化反应仪评估了其光催化降解的性能。实践证明,该综合实验对提高学生的学习兴趣,培养学生的创新思维,锻炼学生的综合实践能力有较大的积极作用。     

负载TiO_2活性炭的制备及催化光降解麦草畏

以废纸为原料,经磷酸活化后与纳米TiO2混合,再经微波加热炭化制备出负载纳米TiO2的活性炭光催化剂,实验测定了该催化剂对麦草畏的吸附性能,其吸附等温线可用Freundlich和Langmuir等温线模型进行回归分析,饱和吸附量为101.2mg/g.该催化剂在紫外光下可降解除草剂麦草畏,和未负载活性炭的纳米TiO2催化剂相比,所制备的催化剂光催化活性更高,有较好的沉降分离性和过滤分离性,有利于光催化剂从溶液中分离和重复使用.     

Fe2O3-CPs-TiO2纳米复合材料的制备、表征及其光催化性能

以苯乙烯单体,TiCl4和Fe3O4为原料,采用两步合成法合成Fe2O3-CPs-TiO2纳米复合材料,并通过UV-Vis、FT-IR、XRD、SEM等技术进行了表征。结果表明,CPs的共轭链上有C=O;且TiO2与CPs间以Ti-O-C键结合;复合微粒的平均粒径为80 nm,复合微粒的小尺寸和共轭键上极性基团的存在有利于Ti-O-C、Fe-O-C键的形成。催化性实验结果表明：在自然光下,该纳米复合材料在45 min内可使染料MB溶液完全脱色。     

可见光响应的掺杂型纳米TiO2制备及其光催化活性研究

在通过溶胶-凝胶法制备出铜和氮共掺杂的纳米二氧化钛(TiO2)的基础上,利用XRD和UV-Vis光谱等技术对其结构、掺杂效果、光催化活性等进行了表征,结果表明,掺入了铜和氮的纳米TiO2结构为锐钛矿晶型,其吸收阈值达到590nm,可见光吸收率比未掺杂的纳米TiO2有了很大提高,最终导致其光催化降解二甲酚橙的活性得到显著增强.     

纳米TiO2／SiO2复合催化剂的制备与表征

以钛酸四丁酯、正硅酸乙酯为前驱体,冰醋酸为水解抑制剂,用溶胶-凝胶法制备了纳米TiO2／SiO2复合物。通过X-射线衍射、红外光谱、比表面积仪等测试手段表明：纳米TiO2／SiO2粒子焙烧后主要以锐钛型存在,有Ti—O—Si键的产生,复合粒子的比表面积达到389m^2/g。     

Characterization and Photocatalytic Activity of Mixed Nanocrystalline TiO_2 Powders Prepared by Xerogel-Hydrothermal Method in Different Acid Solutions

TiO_2 nanoparticles(NPs)were prepared via the hydrothermal route of TiO_2 xerogel in nitric acid, hydrochloric acid and acetic acid. The physico-chemical properties of the powders were characterized by X-ray diffraction(XRD)and N_2 adsorption desorption techniques. The effects of the different acids on the structure(crystal phase)and texture(primary particle size and porosity)of the TiO_2 powders were explored. Results indicated that acetic acid facilitated the formation and stability of pure anatase phase. On the other hand, nitric acid and hydrochloric acid led to the transformation from anatase to rutile. The catalyst synthesized via the hydrothermal route of TiO_2 xerogel in the low concentration hydrochloric acid solution(Ti-HCl-0.15)had the highest photocatalytic activity than the catalysts obtained in the other two acid solutions. The effects of the different acids were discussed in terms of acid strength, chelating effect and the thermal stability of the adsorbed acidic anions.     

Preparation and Photocatalytic Property of CuO/SnO2/TiO2 Nanocomposite

采用溶胶-凝胶法,以硝酸铜、二氯化锡和钛酸四丁酯为原料,加入十六烷基三甲基溴化铵（CTAB）作软模板,制备CuO／Sn02／TiO2纳米复合物。分别用SEM、XRD、IR、UV—vis等对产物进行表征分析,CuO／SnO2／TiO2晶粒由锐钛矿相的TiO2、金红石相的SnO2和单斜晶系的CuO组成。以甲基橙为模拟污染物,研究其催化活性,结果表明CuO／SnO2／TiO2纳米复合物具有较好的光催化活性。     

掺铁TiO2纳米粉体的制备工艺对光催化活性的影响

本研究分别采用了直接沉淀法和共沸蒸馏法制备出掺Fe^3＋量为0．1％的TiO2纳米粉体,用XRD分析方法对晶体的物相和粒径进行了表征。通过在日光源下催化降解水杨酸溶液,对其光催化活性的影响情况进行了比较。结果表明：以共沸蒸馏法制备出的掺Fe^3＋量为0．1％的TiO2纳米粉体在日光下的光催化活性较高。     

纳米TiO2的制备及UV/TiO2体系光催化性能研究

采用回流沉淀法、微波模板辅助法和水热法分别制备了TiO2纳米颗粒,采用XRD对催化剂进行了表征。考察了不同制备方法的催化剂光催化活性。实验结果表明,3种方法制备的TiO2对甲基橙溶液的光催化降解能力较高,采用微波模板辅助法制备的TiO2催化剂催化活性最高,对甲基橙的降解效果最好。催化剂用量为0.4 g,紫外光照射60 min,浓度为12 mg/L的甲基橙溶液降解率为80%。     

Gd和TiO_2共掺杂的WO_3纳米粉体的制备及其光催化性能

以Na2WO4和C16H33(CH3)3NBr为原料,通过液相沉淀法制备了WO3纳米粉体,用钛酸胶体溶液浸滞法制备了TiO2掺杂的WO3纳米粉体,再用Gd(NO3)3溶液浸滞TiO2掺杂的WO3纳米粉体法制备了稀土Gd和TiO2共掺杂的WO3纳米粉体,并采用透射电子显微镜、紫外-可见漫反射吸收光谱和X-射线衍射对其结构进行了表征.实验结果表明,稀土Gd和TiO2共掺杂拓展了WO3的光响应范围,提高了对可溶性染料罗丹明B(RB)的吸附作用,使WO3对RB的光催化降解活性和光稳定性得到了显著提高.     

介孔氧化钛纳米复合材料及电极的制备

以介孔氧化钛为钛源,草酸为碳源,在N2气氛中500℃时进行固相热解,制备介孔碳-氧化钛（C/TiO2）纳米材料,采用溶胶-凝胶方法在C/TiO2上负载Pt纳米颗粒,制成了P/tC/TiO2纳米复合材料,并且在导电玻璃（ITO）上涂膜,制备C/TiO2和P/tC/TiO2电极;用X射线衍射对C/TiO2和P/tC/TiO2的结构进行表征,测定电极的光电化学性能。结果表明：C/TiO2和P/tC/TiO2呈现锐钛晶型,薄膜在0.1mo/lLNa2SO4溶液中具有典型的光电化学活性,P/tC/TiO2和C/TiO2比溶胶-凝胶法制备的TiO2薄膜具有更强的光激发和更稳定的光电流响应性能。     

3D-Bi_2WO_6空心微球的制备及其可见光光催化性能

采用混合溶剂热法成功地制备了空心状3D-Bi2WO6分等级微球。通过X-多晶粉末衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外-可见漫反射(UV-Vis DRS)、比表面测试仪(BET)和光催化降解等手段对所合成材料的组成、结构、形貌、光学、比表面积以及光催化性能进行了表征。讨论了影响3D-Bi2WO6空心微球形成的因素和机理;在可见光照射下,空心状3D-Bi2WO6分等级微球210min内对罗丹明溶液(10-5mol/L,100 mL)的降解率达到了98%,并且性能稳定、易回收。     

一种降解染料有较高日光催化活性的TiO_2薄膜

采用溶胶-凝胶法,制备了TiO2薄膜.利用XRD,SEM,UV-VIS等测试手段进行了样品的表征分析,以降解罗丹明B为反应模型,研究了薄膜的日光催化活性.结果表明,TiO2薄膜有明显的降解效果,显示出良好的催化活性.     

Synthesis and Optimization of TiO_2/Graphene with Exposed {001} Facets Based on Response Surface Methodology and Evaluation of Enhanced Photocatalytic Activity

Response surface methodology(RSM) was employed to optimize the control parameters of TiO_2/graphene with exposed {001} facets during synthesis, and its enhanced photocatalytic activities were evaluated in the photodegradation of toluene. Experimental results were in good agreement with the predicted results obtained using RSM with a correlation coefficient(R~2) of 0.9345. When 22.06 mg of graphite oxide(GO) and 2.09 mL of hydrofluoric acid(HF) were added and a hydrothermal time of 28 h was used, a maximum efficiency in the degradation of toluene was achieved. X-ray diffraction(XRD), transmission electron microscopy(TEM), and scanning electron microscopy(SEM) were employed to characterize the obtained hybrid photocatalyst. The electron transferred between Ti and C retarded the combination of electron–hole pairs and hastened the transferring of electrons, which enhanced the photocatalytic activity.     

TiO2／Cu2O可见光下光催化降解酸性大红的研究

制备了在可见光照射下具有较高催化活性的系列TiO2/Cu2O光催化剂,并用其在可见光下光催化降解酸性大红.研究了TiO2含量和H2O2对光催化反应的影响.结果表明5%TiO2/Cu2O的光催化活性曩好,在加入少量的H2O2情况下酸性大红的脱色率可达到86%,化学需氧量(CODcr)去除率达到65%.     

ZnO/La-TiO2纳米粉体的制备及光催化性能研究

采用水热法制备纳米TiO2粉体,并加入稀土La对其进行改性,得到优化后的纳米La-TiO2粉体.在此基础上,将氧化锌引入到La-TiO2粉体中,得到ZnO/La-TiO2纳米粉体.利用粉末X射线衍射仪(XRD)、同步热分析仪(TG-DSC)、傅里叶变换红外光谱(FTIR)等对其进行结构表征.以甲基橙为光催化降解物,在300W的紫外灯下对其进行降解,实验表明,ZnO/La-TiO2纳米粉体的降解率可达92.57％,比纯二氧化钛的光催化降解率增加了36.58％.     

低损耗TiO_2/Ormosil平面波导的制备及表征(英文)

1IntroductionPlanar waveguides have recently received much at-tention dueto their promising applications inintegratedoptics[1-5].Formation of a waveguide requires a guid-inglayer with the refractive index higher than that ofthe substrate and cladding. The number of guidingmodes depends on thickness and refractive index ofthe guiding layer . Low optical loss is an i mportantproperty of waveguide . Although pure inorganic fil msusing the sol-gel technique have both good mechanicaland thermal st…     

磁性固体超强酸ZrO_2/TiO_2/Fe_3O_4的制备与表征

用化学共沉淀法制得一系列的磁性固体超强酸催化剂,用XRD、IR、Mo|¨ssbauer谱、TEM手段对样品进行了相关方面的理化性质的测定。实验结果表明,随着TiO_2和磁性基质配比的增多,晶型转变温度推迟,延迟了ZrO_2由四方向单斜转化的趋势,磁性基质的引入赋予了固体超强酸以超顺磁性;晶粒生长良好,粒径分布均匀,且磁性固体超强酸显微结构为片状结构,层板取向于[101]方向。     

Study of 2-Propanol Photocatalytic Degradation on Surface of Phase-Ratio-Controlled TiO_2 Nanoparticles

The crystal form of TiO_2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO_2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO_2 on gaseous organic-pollutant photocatalytic degradation, we synthesized a series of TiO_2 nanoparticles with controllable phase ratios. We explored the role of the TiO_2 phase ratio on the photocatalytic activity and degradation pathway in the photodegradation of 2-propanol(IPA). We estimated the crystallite size and crystal proportions of anatase and rutile by X-ray diffraction. We used the Brunauer-Emmett-Teller method to calculate the specific surface area and Fourier transform infrared spectroscopy to characterize the surface chemistry of the samples. Our results show the photocatalytic activities of pure anatase and the sample with 8.6% rutile to be much better than those of the samples with a phase junction and pure rutile. As such, anatase is the better option for the study of photodegradation design and preparation of gas-phase organic pollutants.