Mesoporous Structure and Photocatalytic Activity of Doped Polyanilines

Photocatalytic activity of doped polyaniline nanopowders with different molar ratio of An/O （aniline~oxidizer） has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that doped PANI （polyaniline） nanopowders have the particles size of 30-50 nm with the specific surface area of 20-35 m2.g＂~. It was found that PANI photocatalytic activity essentially depends on molar ratio of An/O and adsorption interactions between the dye molecules and catalytic active centers on PANI surface and these interactions are greatly affected by pH of the solution 9.2. An optimum of the synergetic effect is found for an initial molar ratio of aniline to oxidizer equal to 0.8.     

Ni修饰氧化钛相变的紫外拉曼光谱研究

The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were investigated by using X-ray diffractometry(XRD), UV Raman spectroscopy, TEM, and SEM. It is observed that Ni doping can promote the phase transition and grain size growth of TiO2. Moreover, the propagation of the rutile phase from the bulk into the surface region of TiO2 is increased when the Ni doping amount reaches up to 3%. However, in Ni/TiO2, it is found out that the surface and bulk phase transformation of TiO2 can be inhibited after impregnation of 1% of Ni on the TiO2. Compared with the co-precipitation method, Ni species may be more enriched in the surface of the Ni/TiO2 sample upon adoption of the impregnation method, and the direct contact of anatase particles of TiO2 is avoided. As a consequence, the phase transition in the surface and bulk region of TiO2 can be effectively inhibited by Ni loading. Additionally, the activity of the photocatalytic degradation of RhB on the 3Ni-TiO2-600 ℃ sample is higher than that on the 3 Ni/TiO2-600 ℃ sample. The phase junction formed between anatase and rutile in the surface region of 3Ni-TiO2-600 ℃ may the main reason for its high photocatalytic activity.     

聚乙二醇包覆的TiO2粉体的光催化活性

采用TiCl4水解法制备了被聚乙二醇（PEG）包覆的TiO2粉体,并通过X射线衍射（XRD）、透射电镜（TEM）对粉体的物相组成及表面形貌进行表征。将合成的TiO2粉体用于2,4-二氯苯氧乙酸（2,4-DPA）的降解反应中,利用荧光光度计以及紫外可见分光光度计等技术手段,考察溶液的荧光及紫外吸收强度随光照时间的变化关系,并以此判断包覆的TiO2的光催化性能。结果表明：PEG包覆的TiO2能降低2,4-DPA溶液的荧光强度和紫外吸收强度,有明显的光催化降解作用,且以相对分子质量较大的PEG包覆的效果较好。     

氮和镍掺杂纳米TiO2复合粉体的制备及其光催化性能

以Ti（SO4）2,NiSO4·6H2O,N,N-二甲基甲酰胺等为原料,采用水热合成法制备氮和镍掺杂的纳米TiO2复合粉体,通过XRD对其进行了表征,并以10mg／L的甲基橙溶液为底物,测定了其太阳光催化性能。结果表明,氮和镍掺杂能提高纳米TiO2的光催化性能,当氮和镍掺杂摩尔分数均为2．0％,焙烧温度为600℃,甲基橙溶液的pH值为5时,光催化性能最高,甲基橙溶液太阳光照射5h后降解率达到98．1％。     

纳米二氧化钛光催化还原二氧化碳的研究

二氧化碳是引起全球温室效应的气体之一,在温和条件下,通过光催化转化将二氧化碳资源化的研究具有重大的现实和理论意义。本文研究了纳米二氧化钛光催化还原二氧化碳反应条件,考察了二氧化钛粒径对光催化还原性能的影响。     

超临界流体干燥法制备纳米TiO_2

以廉价的无机盐为原料,采用液相化学法结合超临界流体干燥法制备纳米TiO2,并采用TEM、XRD等手段对其物性进行表征,考察水溶胶pH、表面活性剂、陈化时间、钛盐浓度、氨水浓度对纳米TiO2粒径、形貌、收率的影响。同时还发现超临界流体干燥法可实现干燥、晶化一步完成。与普通干燥法相比,超临界流体干燥法制备的TiO2纳米粒子具有粒径分布均匀、粒径大小可控、纯度高、热稳定性好等优点。     

Cu~(2+)/TiO_2-SiO_2催化剂的制备及其光催化降解气相间二甲苯的性能

以钛酸丁酯、正硅酸乙酯和硝酸铜为主要原料,采用溶胶-凝胶法制备了Cu2+/T iO2-S iO2催化剂,分别用X射线衍射、BET比表面积测试、透射电子显微镜、紫外-可见光谱和傅里叶变换红外光谱对其进行了表征;以间二甲苯为代表物,评价了Cu2+/T iO2-S iO2催化剂对气相挥发性有机物的光催化降解活性,并讨论了复合S iO2和掺杂Cu2+的Cu2+/T iO2-S iO2催化剂对光催化降解间二甲苯活性的影响。实验结果表明,在500℃煅烧后的Cu2+/T iO2-S iO2催化剂呈锐钛矿结构,粒子分布均匀,平均粒径为9nm,比表面积为285m2/g;掺杂Cu2+促进了Cu2+/T iO2-S iO2催化剂对可见光的吸收,显著提高了光量子效率。用Cu2+/T iO2-S iO2催化剂光催化降解质量浓度100m g/L的气相间二甲苯,反应240m in后,间二甲苯的降解率达96.4%。     

Synthesis,characterization and comparative study of nano-Ag–TiO2 against Gram-positive and Gram-negative bacteria under fluorescent light

Currently, some of the major problems affecting the world are air pollution as well as microbial contamination. Every time we breathe, we are risking our lives by inhaling dangerous chemicals and biological contaminants that have found their way into the air. Therefore this work focuses on the antibacterial activity of Ag–TiO₂ to overcome the microbial contaminant and infectious disease. Ag–TiO₂ nanosolution were synthesized by sol–gel method and found to be an effective visible light driven photocatalyst. The nanosolutions were characterized by X-ray diffraction (XRD), transmittance electron microscopy (TEM), photoluminescence (PL) spectra, and X-ray photoelectron spectroscopy (XPS). At the concentration of 0.2–0.1 M, Ag–TiO₂ caused 100% inhibition of bacterial growth. The antibacterial efficacy of Ag–TiO₂ was evaluated with two kinds of bacteria; Gram-positive and Gram-negative. The colony count of Ag–TiO₂ against Gram-negative were evaluated with stain such as Escherichia coli, Pseudomonas aeruginosa and Shigella while for Gram-positive were investigated with Staphylococcus aureus, Bacillus subtilis, Bacillus cereus. Colony count results indicated that Ag–TiO₂ able to kill bacteria at the lowest concentration of 0.05 M that contains 0.06 mol % Ag. From the SEM and TEM observation, the survival of the Gram-positive was low and the decomposition was rapid as compared to Gram-negative bacteria.     

聚丙烯/蒙脱土纳米复合树脂的结构、形态与性能

利用球形纳米蒙脱土(MMT)负载Ziegler-Natta催化剂制备了聚丙烯(PP)/MMT纳米复合树脂。复合树脂中的PP具有与普通PP相仿的等规度和熔点;可通过改变聚合条件调节复合树脂中PP的相对分子质量和MMT含量。采用SEM,WAXRD,POM,DMA,TG等方法研究了复合树脂的形态结构、结晶形态、流变行为、动态力学行为、力学性能、阻隔性能和热稳定性。表征结果显示,复合树脂颗粒呈球形,流动性良好;MMT片层均匀分散于PP基体中,MMT片层与PP基体的相容性较差,在熔融加工过程中会发生部分聚集。当MMT含量约为1.1%(w)时,复合树脂中可形成MMT的逾渗网络。当MMT含量为1.29%(w)时,复合树脂的综合力学性能较好。少量MMT的存在可提高复合树脂的液体阻隔性能和热稳定性。     

Preparation of Cu-BiVO4 and Its Photocatalytic Properties for Desulfurization of Model Oil

A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.     

Photocatalytic study of some synthesized MWCNTs/TiO2 nanocomposites used in the treatment of industrial hazard materials

Multi-walled carbon nanotubes/titanium dioxide nanocomposites were successfully synthesized by Sol-Gel method using new different ratios of tetrabutyl titanate and functionalized MWCNTs as the starting precursors. The synthesized Multi-walled carbon nanotubes/different titanium dioxide percentages (MWCNTs/3, 6 and 10%TiO₂) nanocomposites were characterized using XRD, SEM and N₂ Adsorption-Desorption techniques. The optical band gap was estimated for MWCNTs and MWCNTs with different TiO₂ percentages by Kubelka-Munk equation giving 3.72, 2.92, 2.83, 2.71 eV values respectively. The synthesized nanocomposites were used as photocatalyst for decontamination of two local textile Dianix Blue and Vat Green 1 Dyes which commonly used in dyeing manufacture in local market.     

TiO_2纤维的制备、表征及其光催化活性

采用常压乙二醇法制备出在可见光下具有较高催化活性的TiO2纤维。扫描电子显微镜表征结果表明,TiO2纤维直径为0.8～2.0μm、长度为5～25μm;BET比表面积和X射线衍射表征结果表明,随焙烧温度的升高,比表面积减小,TiO2纤维晶型逐渐由锐钛矿型向金红石型转变;紫外-可见漫反射光谱分析结果表明,TiO2纤维在可见光区有明显的吸收。在可见光下对甲基橙和苯酚的降解实验表明,焙烧温度为400℃时TiO2纤维的催化活性最好,对甲基橙和苯酚的降解率分别达到90.3%和84.0%;所制备的TiO2纤维比溶胶-凝胶法制备的锐钛矿型TiO2在可见光下具有更好的催化活性,原因是其能带间隙减小和吸收波长扩展到可见光区所致。     

Photocatalytic Oxidation Kinetics of Thiophene with Nano-F-/Fe3+/TiO2

Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO2(nano-F/Fe3+/TiO2)powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F-/Fe3+/TiO2 on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F-/Fe3+/TiO2 was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F-/Fe3+/TiO2 catalyst was of first-order with a rate constant of 0.6508 h-1 and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1% in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm The reaction rate constant increased with a decreasing initial concentration of thiophene.     

纳米TiO2光催化处理乙烯工业废水的研究

以纳米二氧化钛作为光催化剂,对乙烯工业废水进行降解实验研究,考察了常温下催化剂的用量、光照时间及pH值等因素对工业废水处理效果的影响,筛选出最佳的光催化处理工艺条件。在最佳处理工艺条件下,COD和氨氮的降解率分别达到94．1％和84．5％。     

乳液插层法制备丁腈橡胶-有机蒙脱土纳米复合材料的结构与性能

采用乳液插层法制备了丁腈橡胶(NBR)-有机蒙脱土(OMMT)纳米复合材料;用TEM技术对纳米复合材料的微观结构进行了表征;并研究了OMMT添加量对纳米复合材料的力学性能、耐溶剂性、耐低温性和热稳定性的影响。实验结果表明,用该法制备的NBR-OMMT纳米复合材料是一种插层型的纳米复合材料,其力学性能随OMMT添加量的增加而增强,具有优异的耐溶剂性和耐低温性。TG分析结果显示,添加30份(质量份数)OMMT时,纳米复合材料的最大降解率温度较NBR提高了约10℃,具有优异的热稳定性。     

PMoV／TiO2光催化降解甲基橙反应条件优化及动力学研究

溶胶-凝胶法制备光催化剂PMoV／TiO2光催化降解甲基橙溶液,考察了催化剂用量、氧化剂用量、光强度和甲基橙染料溶液浓度对降解反应的影响。结果表明,在甲基橙染料溶液初始浓度为6mg／L,催化剂PMoV／TiO2用量0．12g,氧化剂双氧水用量8mL,晴天光照条件下,甲基橙染料溶液脱色率达90．79％。最后,研究了该光催化反应的动力学过程。     

低温溶液法制备TiO2/γ-AlO(OH)纳米复合粉体及其光催化性能

以硝酸铝为铝源,钛酸四丁酯为钛源,柠檬酸三铵为起泡剂,聚乙烯吡咯烷酮(PVP)作表面活性剂,采用低温溶液法制备TiO2/γ-AlO(OH)复合纳米粉体光催化剂;采用HRTEM、FESEM、EDS、XRD、紫外-可见漫反射光谱(UV-Vis DRS)和N2吸附-脱附(BET)等手段对复合材料进行表征;研究了γ-AlO(OH)掺杂量、PVP表面活性剂等对TiO2/γ-AlO(OH)复合纳米粉体的形貌及光催化活性的影响规律;探究了吸附作用对催化剂活性的影响。结果表明：载体材料γ-AlO(OH)纳米微球的介孔结构限制了TiO2纳米晶的团聚和长大,适当添加PVP表面活性剂可以减少复合粉体团聚,并调控其微观形貌;当γ-AlO(OH)掺杂质量分数为10%、PVP添加量为0.1 mmol时,制备的TiO2/γ-AlO(OH)复合粉体的BET比表面积为334.27 m2/g,催化性能最佳,光照30 min,对罗丹明B的降解效率为94.26%,远大于纯锐钛矿结构TiO2和市售P25催化剂。     

Spectroscopic Investigated Interaction between Silver Nanocomposites Based of Poly-N-Vinylpyrrolidone and Doxorubicin for Drug Delivering

It is investigated to synthesis of Ag nanoparticles by presence the synthetic polymer poly-N-vinylpyrrolidone. It was determined with X-ray analyses that the size ofnanoparticles changed between 18-42 nm. Then, the authors studied sorption process of doxorubicine by silver nanocomposites and investigated chemical interaction between antibiotic and poly-N-vinyplyrrolidone with UV-VIS （ultraviolet visible） and FT-IR （Fourier transform infrared） spectroscopy. It is shown that formation of the nanoparticles doxorubicin complex mainly occurs in the 190-208 nm wavelengths on polymers 〉C=O functional groups. Also, the four main absorbing peaks of doxorubicin--234, 253, 288 and 495 nm undergo chemists shift （A2 = 12-15 nm）. When increases to pH = 7-8, the size of Ag-doxorubicin particles decreases. It is determined that the 410 nm absorption peak of Ag nanoparticles undergo 409-418 nm interval and the 3,500, 1,600, 1,645 and 1,190 sm^-1 absorption lines of PVPr （polymer poly-N-vinylpyrrolidone） slightly altered.     

水热法制备纳米Mn(Ⅱ)/TiO_2粉体及其日光催化活性的研究

采用水热法,在温和的条件下制备了具有较高光催化活性的Mn(Ⅱ)/TiO2光催化剂,采用X射线粉末衍射、扫描电镜、紫外可见漫反射手段对其进行了表征。在太阳光照射下,以罗丹明B溶液的降解为模型反应,研究了光催化剂的催化活性。研究结果表明,TiO2晶型为单一的锐钛矿相,光响应波长由纯TiO2的380nm拓宽到400nm以上,达到可见光区范围,新型改性的Mn(Ⅱ)/TiO光催化剂的日光催化活性比较高。     

Effect of Dispersity and Porous Structure of TiO2 Nanopowders on Photocatalytic Destruction of Azodyes in Aqueous Solutions

Photocatalytic activity of TiO2 nanopowders of anatase modification with various particle sizes and specific surface areas has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue and direct blue 2C azodyes. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that TiO2 nanopowders have the particles size of 5-120 nm with the specific surface area of 15-120 m2·g^-1. The used TiO2 samples are characterized by mesoporous structures with average pore size of 4.3-14.9 nm. The photocatalytic activity of TiO2 was evaluated via decolorization of azodyes solutions. It was shown that the efficiency of decolorization symbatically changes with the dye adsorption value on TiO2 surface and the degree of decolorization rises when the surface area of TiO2 nanopowders increases. It was found that TiO2 photocatalytic activity essentially depends on adsorption interactions between the dye molecules and catalytic active centers on TiO2 surface, and these interactions, in turn, are greatly affected by pH of the solution.