凹凸棒土负载TiO_2光催化剂的制备、表征和性能研究

为考察光催化技术对染料废水的降解作用,选择新的催化剂载体-微米凹凸棒土,采用溶胶-凝胶法制备TiO2/凹凸棒土光催化剂.X-射线衍射谱图显示,产品表面的衍射峰与TiO2的特征峰相吻合.能量色散谱图显示,包覆后凹凸棒土原有的Al、Mg、Fe、K、Si的谱峰已消失或减弱,而以Ti、O的谱峰为主,表明其表面包覆良好.在光化学反应器中,以紫外灯为光源,亚甲基蓝为模拟底物,研究了TiO2/凹凸棒土的光催化性能.实验制得的TiO2/凹凸棒土催化剂对亚甲基蓝的脱色率受pH值、催化剂用量、亚甲基蓝初始浓度等因素的影响.在选定的实验条件下,在30 min之内,TiO2/凹凸棒土对亚甲基蓝的脱色率达到90%以上.与单独用TiO2处理的效果相比,负载型催化剂对染料底物的脱色率提高了1倍以上.     

TiO2／海泡石光催化剂的制备及其对染料废水脱色效果的研究

以钛酸丁酯为原料,海泡石为载体,采用溶胶一凝胶法合成TiO2／海泡石光催化剂,经xRD分析表明,TiO2以锐钛矿型结构分布在海泡石表面．通过亚甲基蓝溶液降解脱色实验,检验了试样的光催化性．实验表明,200mL的浓度不大于20mg／L的亚甲基蓝溶液中,光催化剂投加量为2g时,光催化效果最好．催化反应在很短的时间内即能达到较高的脱色率,150min后的脱色率可达到96％以上．     

TiO2光催化剂的制备及其降解甲基橙的研究

采用溶胶凝胶法在不同条下制备出了纳米二氧化钛光催化剂,通过正交实验优化出了光催化剂的最佳制备条件,并研究了不同因素对甲基橙脱色率的影响。结果表明,不同pH值下,TiO2对甲基橙的脱色率影响不大;随着甲基橙初始浓度的增加脱色率下降;试验条件下TiO2的最佳投加量为0.1g/L。     

掺杂镝和钴纳米TiO2光催化剂的溶胶-凝胶法制备及其性能

采用溶胶-凝胶法,制备TiO2、Co2 /TiO2、Dy3 /TiO2、Co2 ,Dy3 /TiO2光催化剂.通过考察掺杂离子的种类和用量对所得催化剂用于紫外光催化降解亚甲基蓝性能的影响,得出Dy3 /TiO2中Dy3 的适宜掺杂量为1.0%(质量分数),Co2 ,Dy3 /TiO2中,当Dy3 的掺杂量为1.0%时,Co2 的适宜掺杂量为0.2%,相应的脱色效率为98.79%.当掺杂量适当时,4种催化剂用于紫外光催化降解亚甲基蓝的活性次序为:Dy3 /TiO2>Co2 ,Dy3 /TiO2>TiO2>Co2 /TiO2.XRD分析结果表明,所得光催化剂均为纳米粒子.     

P掺杂TiO2的制备及光催化性能的研究

采用溶胶-凝胶法(Sol-gel)制备掺杂P的纳米TiO2光催化剂,将焙烧温度、焙烧时间、冰醋酸与钛酸四丁酯物质的量比、P/Ti物质的量比、加水量和乙醇用量等因素作为实验考察条件,分别在紫外光和可见光条件下,研究P掺杂TiO2制备条件对其光催化降解有机污染物性能的影响。以难生化降解的亚甲基蓝为目标降解物,通过其降解前后浓度的变化考察改性光催化剂的光催化活性。结果表明,适量P的掺杂能够有效促进TiO2纳米粒子的光催化活性。利用溶胶-凝胶法制得的光催化剂,最佳催化剂制备条件为:P掺杂的摩尔分数为6%,600℃焙烧120min,冰醋酸与钛酸四丁酯物质的量比为3∶1,加水体积80mL,乙醇体积60mL,此条件下亚甲基蓝可见光降解率为88.0%。     

La3+-Fe3+共掺杂纳米TiO2粉体的光催化性能

采用溶胶-凝胶法制备了La3 -Fe3 共掺杂的TiO2纳米粉体,并以亚甲基蓝溶液为目标降解物研究了掺杂纳米TiO2粉体在紫外光作用下的光吸收和光催化性能.通过XRD和TEM等测试技术对样品的晶型、形貌和粒径尺寸进行了表征.结果表明,La3 -Fe3 共掺杂制备的TiO2粉体最佳热处理温度为550 ℃,结晶完整、主晶相为锐钛矿型,平均粒径约为20 nm;掺杂使TiO2吸收带发生红移,光催化性能增强;共掺杂体系的最佳量为n(La3 ):n(TiO2)=0.05%,n(Fe3 ):n(TiO2)=0.5%.共掺杂的TiO2粉体对亚甲基蓝有良好的降解效果,反应2 h降解率达到98.72%,优于同等条件下制备的未掺杂的纯TiO2粉体.复合掺杂光催化剂对亚甲基蓝的降解遵循一级动力学方程.     

微乳液制备负载型共掺杂TiO2光催化剂及性能研究

采用反相微乳液法制取了La3+,Fe3+共掺杂TiO2/活性白土光催化剂,用UV-Vis光谱对其紫外可见光区吸收性能进行了表征.考察了La3+,Fe3+共掺杂对TiO2/活性白土可见光催化性能的影响以及溶液pH值等对甲基橙脱色率的影响.实验结果表明,La3+,Fe3+共掺杂有协同作用,其吸收边带红移比La3+或Fe3+单元掺杂的更多,对可见光的吸收也比单元掺杂更强;太阳光照射下1.0%La3+-0.3%Fe3+-TiO2/活性白土对甲基橙脱色率达到48%,大于单一La3+或Fe3+掺杂样品的脱色率(45%和30%);甲基橙溶液pH=4时,其脱色率最大;日光照射反应时间超过6 h后,甲基橙脱色率升高幅度变得缓慢.     

Bi_2O_3/TiO_2复合光催化剂对甲基橙的光催化作用

以溶胶-凝胶法制备了Bi2O3/TiO2复合光催化剂,用TEM、HRTEM、XRD、Raman、FTIR、PL、UV-Vis DRS等对其结构、性质进行表征,并以甲基橙为有机污染物对Bi2O3/TiO2复合光催化剂活性进行研究。结果表明:复合少量Bi2O3可抑制TiO2由锐钛矿相到金红石相相变及其颗粒的生长。n(Bi)∶n(Ti)=0.017 5配比的Bi2O3/TiO2复合光催化剂活性最好,当用量为2.5g/L时,25mg/L的甲基橙溶液在500 W氙灯下照射5h后,脱色率达到99.4%,2.1倍于Degussa P25TiO2。     

水热法制备海绵钛负载二氧化钛膜及性能研究

以多孔海绵钛为载体,2 mol/L H2O2为氧化剂,0.15 mol/L KOH为矿化剂,在水热条件下一步合成了颗粒大小约为0.5 μm的四方状锐钛矿海绵钛负载TiO2膜.以XRD、SEM观察海绵钛负载TiO2膜晶型、形貌,以亚甲基蓝为目标降解物研究了其光化性能催化,并探讨了水热时间对产物TiO2膜晶型、形貌及光催化性能的影响.结果表明,12 h为最佳水热时间,海绵钛负载TiO2膜有着最佳的光催化性能:光催化反应60 min,亚甲基蓝溶液的降解率达99%.采用该法制备的TiO2光催化剂回收简单,反复利用后,其光催化性能无明显下降.     

负载纳米TiO2、Ag复合微胶囊光催化性能的研究

以纳米Ag粒子掺杂光催化剂TiO2,采用原位聚合法成功制备负载纳米TiO2/Ag的复合微胶囊;利用扫描电子显微镜、紫外-可见吸收光谱等测试手段对其形貌和光谱性质进行了表征,探讨不同纳米TiO2、Ag加入量的微胶囊在不同光催化时间下对亚甲基蓝光催化效果的影响.结果表明:纳米Ag(1.94%)掺杂TiO(22.78%)的复合微胶囊对亚甲基蓝具有最大脱色率为10.82%,单独添加纳米TiO2和单独添加纳米Ag粒子的微胶囊样品与常规微胶囊比较没有显著差异.     

Fe3+-TiO2/SiO2气相光催化降解乙醛反应动力学研究

用浸渍法制备了Fe^3 -TiO2／SiO2负载型光催化剂,并进行了光催化降解气相中乙醛的实验和动力学研究．结果表明,Fe^3 掺杂量(nFe3 ／nTi4)为0．5％时光催化降解乙醛的效率最高;水气的存在提高了Fe^3 -TiO2／SiO2负载型催化剂的光催化活性,但使Fe^3 -TiO2纳米粉的光催化活性降低;O2的存在使Fe^3 -TiO2纳米粉和Fe^3 -TiO2／SiO2负载型催化剂的催化活性均有所降低;光强减弱使乙醛降解率下降,反应速率与光强之间呈近似线性关系;光催化降解气相中乙醛的动力学可以用Langrauir-Hinshelwood动力学方程描述．     

磁性纳米TiO2/Fe3O4复合材料的制备及光催化降解性能

采用均匀沉淀法在Fe3O4表面包覆TiO2,制备新型纳米TiO2/ Fe3O4光催化材料,并通过改变pH值、温度、TiO2/Fe3O4的比例和硫酸钛浓度等得到材料制备的最佳条件.用X射线衍射分析了复合颗粒的形态结构及包覆情况.通过可溶性染料活性艳红X-3B的降解反应,考察了光催化活性.结果表明,用最佳条件制备的复合材料对活性艳红的脱色率达97.12%.光降解动力学结果表明:对活性艳红X-3B染料的光催化降解反应符合一级反应动力学.     

纳米TiO2/矿物复合光催化降解染料废水研究

直接热舍Fe2O3制备纳米TiO2／高岭石复合光催化材料。用XRD、FYIR、Raman技术对材料的晶体结构和分子结构进行表征分析。偶氮染料废水初始浓度40mg／L，催化剂添加量2g／100mL废水，废水初始pH=4，紫外光和太阳光下6h后偶氮废水降解脱色率分别为98．4％和62．5％。     

Magnetically Recoverable PEI/Titanate@Fe_3O_4 Photocatalysts: Fabrication and Photocatalytic Properties

The magnetically separable ternary polyetherimide/titanate@Fe_3 O_4(PTF) photocatalysts of special heterostructure between magnetite(Fe_3 O_4) microspheres and titanates nanosheets modified by polyetherimide(PEI) were successfully fabricated via a simple facile hydrothermal deposition method. The as-prepared photocatalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Transmission electron microscopy and UV-vis diffuse reflectance spectroscopy etc. The results showed that the as-fabricated material had a structure of Fe_3 O_4 microspheres coated with titanates nanosheets modified by PEI. The special interfacial contact between 3 D microsphere and 2 D nanosheets in the nanoarchitectures was formed via electrostatic attraction. Furthermore, the resulted photocatalysts were tested by degradation reaction of methylene blue under visible light irradiation and demonstrated an enhanced performance than the pure Fe_3 O_4 microspheres, and the photocatalytic activity enhanced with the molar ratio of Fe_3 O_4 microspheres and modified titanate gradually, which was attributed to the expansion of the surface area and the different electrostatic contact between the Fe_3 O_4 microspheres and titanate nanosheets. Moreover, the obtained results revealed the high yield magnetic separation and efficient reusability of PTF-5(96.7%) over 3 times reuse.     

Facile Fabrication of Fe_2O_3/Nitrogen Deficient g-C_3N_(4-x) Composite Catalysts with Enhanced Photocatalytic Performances

The modification of graphitic carbon nitride can significantly improve the photocatalytic performance of graphitic carbon nitride(g-C_3N_4). Fe_2O_3/nitrogen-deficient g-C_3N_(4-x) composite catalysts were prepared with dicyandiamide as the precursor and Fe~(3+) doped in this study. The composite catalysts were characterized by XRD, SEM, FT-IR, XPS and photocurrent measurements. Close interaction occurred between Fe_2O_3 and nitrogen deficient g-C_3N_(4-x), more photogenerated electrons were created and effectively separated from the holes, resulting in a decrease of photocarrier recombination, and thus enhancing the photocurrent. Photocatalytic performance experiments showed that Fe_2O_3/nitrogen deficient g-C_3N_(4-x) could utilize lowenergy visible light more efficiently than pure g-C_3N_4, and the removal rate was 92% in 60 minutes.     

The structure and properties of Fe3O4／P （NaUA-St-BA）magnetic composite nano particles

Fe3O4/P (NaUA-St-BA) core-shell composite micro spheres were in situ prepared by soapless polymerization of styrene and butyl acrylate, with Fe3O4 magnetic colloidal particles coated with NaUA. The results of IR and XRD analysis demonstrated that the desired polymer chains have been covalently bonded to the surface of Fe3O4 nano particles. The morphology analysis by TEM confirmed that the composite particles have the core-shell structure and a relatively uniform diameter of about 100nm. The magnetic properties of the obtained composite latex particles were measured by VSM and found that they exhibited super paramagnetic properties.Finally, the prepared magnetic composite particles latex is stable for several months.     

功能化Fe_3O_4对水中亚甲基蓝染料的吸附性能研究

通过共沉淀法制备了磁性Fe_3O_4纳米粒子,并将其表面包覆二氧化硅外壳,制备了性质稳定,脱色性能较好,同时易于固液分离的功能化磁性纳米粒子.以模拟印染废水的脱色为目标,研究了pH、温度、吸附时间等因素对脱色效果的影响.研究结果表明,磁性吸附剂制备成本低,对亚甲基蓝溶液的脱色效率显著.     

Preparation and Characterization of Superparamagnetic Fe_3O_4/CNTs Nanocomposites Dual-drug Carrier

Fe_3O_4/carbon nanotubes(Fe_3O_4/CNTs) nanocomposites were prepared by polylol hightemperature decomposition of the precursor ferric chloride and CNTs in liquid triethylene glycol.After surface modification with hexanediamine,folate was covalently linked to the amine group of magnetic Fe_3O_4/CNTs nanocomposites.The products were characterized by Fourier-transform infrared spectroscopy,transmission electron microscopy,and vibrating sample magnetometry.Then Fe_3O_4/CNTs were used as a dual-drug carrier to co-delivery of the hydrophilic drug epirubicin hydrochloride and hydrophobic drug paclitaxel.The results indicated that the Fe_3O_4/CNTs had a favorable release property for epirubicin and paclitaxel,and thus had potential application in tumor-targeted combination chemotherapy.     

Adsorption of BSA on Carbon-coated Fe_3O_4 Microspheres Activated with 1-ethyl-3-(3-dimethylaminopropyl)-Carbodiimide Hydrochloride

Carbon-coated Fe_3O_4( Fe_3O_4/C) microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC) were prepared, characterized and applied to adsorb bovine serum albumin(BSA). The prepared magnetic microspheres had spherical core-shell structure with a uniform and continuous carbon coating coupled with activation by EDC, and possessed superparamagnetic characteristics. The experimental results showed that the adsorption amount of BSA on the EDC-activated Fe_3O_4/C(Fe_3O_4/C-EDC) microspheres was higher than that on the Fe_3O_4/C microspheres. The maximum adsorption of BSA on Fe_3O_4/C-EDC microspheres occurred at pH 4.7, which was the isoelectric point of BSA. At low concentrations(below 1.0 M), salt had no noticeable effect on BSA adsorption. The BSA adsorption of Fe_3O_4/C-EDC microspheres had a better fit to the Langmuir model than the Freundlich isotherm and Temkin isotherm model, and the kinetic data were well described by the pseudo-second-order model. The adsorption equilibrium could be reached within 20 min. High desorption efficiency(97.6%) of BSA from Fe_3O_4/C-EDC microspheres was obtained with 0.5 M Na_2HPO_4(pH 9.4) as the desorbent.     

磁性纳米TiO_2粉体的制备

使用自制的高强度机械搅拌反应器,通过两种不同的方案制备了磁性纳米TiO_2粉体。通过X射线衍射图谱对其晶体结构进行分析,透射电镜观测纳米粒子的粒径和分散性,VSM图比较它们的磁性能。结果表明：在本实验条件下,将Fe_3O_4混合于氨水溶液中,与Ticl,溶液反应后通过冷冻干燥的方法得到的磁性纳米TiO_2粉体纯度高,粉体分散性好,粒径分布范围窄,并且具有较好的超顺磁性。