Influence of Calcination Temperature on TiO2 Nanotubes' Catalysis for TiO2/UV/O3 in Landfill Leachate Solution

The influence of calcination temperature on TiO2 nanotubes' catalysis for TiO2/UV/O3 was investigated. TiO2 nanotubes (TNTs) were prepared via the sol-gel method and calcined at 300-700℃, which were labeled as TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700, respectively. TNTs were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). It is found that TNTs calcined at 400 ℃ showed the best thermal stability. When the calcination temperature increased from 400 ℃ to 700 ℃, the special structure of tubes was destroyed and gradually converted into nanorods and/or particles. The transformation from anatase to rutile occurred at 600 ℃, and the rutile phase was enhanced when the calcination temperature was increased to over 600 ℃. The calcina-tion temperature's influence on TNTs' adsorption activity for chemical oxygen demand (COD) and catalytic activity for TiO2/UV/O3 was investigated in landfill leachate solution. In landfill leachate solution, the adsorption activity of COD decreased in the reduced order of TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700. In photocatalytic ozonation, TNTs-400 showed the best catalytic activity while TNTs-700 exhibited the worst. In other three processes, the COD removal of TNTs-300/UV/O3 was higher than those of TNTs-500/UV/O3 and TNTs-600/UV/O3 in the first 20 min, and then became close to those of the latter two in the following 40 min. Compared with TNTs-300 and TNTs-400, TNTs-600 had the best anti-fouling activity, while TNTs-500 and TNTs-700 had lower anti-fouling activity than the former three. In photocatalytic ozonation, the calcination temperature of 400 ℃ was appropriate when TNTs were obtained at the synthesis temperature of 105 ℃.     

应用固相微萃取技术检测茶汤中的菊酯类农药残留

探讨了单壁碳纳米管SPME纤维的制备,并应用SPME/GC技术直接检测茶汤中的菊酯类农药残留.该方法在优化的条件下,6种菊酯类农药的检测限为0.01-0.05ng/mL,线性范围0.1-50.0ng/mL.相关系数R2在0.96以上,相对标准偏差为4.1-11.7%.所建立的SPME/GC法具有分析速度快、无需任何有机溶剂、灵敏度高等特点,在茶汤中菊酯残留的快速分析领域应具有较好的应用前景.     

Cu（II）和Ni（II）对四环素在官能团化碳纳米管上吸附的影响

研究目的：探究四环素在不同官能团化碳纳米管上的吸附机制,并揭示Cu（II）和Ni（II）对四环素与碳纳米管间作用的影响机制。创新要点：1.碳纳米管对四环素的吸附与其表面官能团种类密切相关;2.金属离子对碳纳米管吸附四环素的影响能力与金属离子络合性能相关。研究方法：采用批量吸附试验和谱学手段表征相结合的研究方法。重要结论：四环素在不同官能化碳纳米管上吸附能力的强弱顺序为：石墨化碳纳米管（G-MWCNTs）〉羟基化碳纳米管（OH-MWCNTs）〉羧基化碳纳米管（COOH-MWCNTs）〉氨基化碳纳米管（NH2-MWCNTs）,碳纳米管表面的官能团类型和数量对四环素与碳纳米管间的作用机制有重要影响（表1和图2）。Cu（II）和Ni（II）对四环素在G-MWCNTs 上的吸附几乎没有影响,但对在其它三种官能团化的碳纳米管上的吸附表现出不同的影响能力（图3）。与Ni（II）相比,Cu（II）与碳纳米管上官能团具有更强的络合能力,因此Cu（II）对四环素在不同碳纳米管上吸附的影响要比Ni（II）更显著。     

MWCNT—Nafion复合修饰电极伏安法测定痕量Zn^2＋

由于Nation的强离子交换能力和多壁碳纳米管(MWCNTs)卓越的性能,一种高灵敏度、无汞的基于MWCNT-Nafion复合修饰玻碳电极测定痕量Zn2+的新方法被建立.在0.01 mol/dm3 KCl(pH=7)溶液中,采用阳极溶出伏安法(ASV)在MWCNT-Nafion复合修饰电极上检测Zn2+.实验结果表明伏安图上能出现一灵敏的氧化峰,峰电位为-1.05 V,利用该峰可以进行痕量Zn2+的检测.峰电流与Zn2+浓度在2.0×10-12～1.0×10-10 mol/dm3的范围内呈良好线性关系,相关系数为0.998,检出限为0.2×10-13mol/dm3.这种方法为痕量Zn2+的检测提供了新手段.     

姜黄素-碳纳米管-离子液体修饰电极对盐酸羟胺电催化氧化性能研究

以N-辛基吡啶六氟磷酸盐离子液体为分散剂,制备羧基碳纳米管-离子液体均匀分散体系,制备碳纳米管修饰电极。并通过电化学沉积,制备得到姜黄素-碳纳米管-离子液体修饰电极。修饰电极的电化学性能研究表明,该电极具有较低的背景电流响应,对盐酸羟胺具有明显的电化学催化氧化作用。阳极电位为0.25 V时,盐酸羟胺在修饰电极上氧化电流显著增大,在5.0～455μmol/L浓度范围内,氧化电流和盐酸羟胺浓度呈线性响应。     

反应条件对碳纳米管产率的影响

用镍铝催化剂催化裂解甲烷制备了碳纳米管;研究了反应温度及反应气氛对制备碳纳米管产率的影响。结果表明,碳纳米管的产率随温度的增加先增加,后减小,在550～650℃出现最大值,说明此温度范围最适合碳纳米管的生长;氢气预还原可以提高催化剂的反应活性。反应过程通氢气不但能提高催化剂的活性,同时也能提高产物的质量．上述两种情况均能提高碳纳米管的产率。     

Reagentless biosensor based on layer-by-layer assembly of functional multiwall carbon nanotubes and enzyme-mediator biocomposite

A simple and controllable layer-by-layer (LBL) assembly method was proposed for the construction of reagentless biosensors based on electrostatic interaction between functional multiwall carbon nanotubes (MWNTs) and enzyme-mediator biocomposites. The carboxylated MWNTs were wrapped with polycations poly(allylamine hydrochloride) (PAH) and the resulting PAH-MWNTs were well dispersed and positively charged. As a water-soluble dye methylene blue (MB) could mix well with horseradish peroxidase (HRP) to form a biocompatible and negativelycharged HRP-MB biocomposite. A (PAH-MWNTs/HRP-MB) _n bionanomultilayer was then prepared by electrostatic LBL assembly of PAH-MWNTs and HRP-MB on a polyelectrolyte precursor film-modified Au electrode. Due to the excellent biocompatibility of HRP-MB biocomposite and the uniform LBL assembly, the immobilized HRP could retain its natural bioactivity and MB could efficiently shuttle electrons between HRP and the electrode. The incorporation of MWNTs in the bionanomultilayer enhanced the surface coverage concentration of the electroactive enzyme and increased the catalytic current response of the electrode. The proposed biosensor displayed a fast response (2 s) to hydrogen peroxide with a low detection limit of 2.0×10⁻⁷ mol/L (S/N=3). This work provided a versatile platform in the further development of reagentless biosensors.     

磁场方向对碳纳米管氢等离子体微波吸收的影响

深入研究了外加磁场的方向对碳纳米管薄膜中氢等离子体电磁波衰减性能的影响。根据磁离子理论和W．K．B半经典近似法,理论推导了外加静磁场方向和微波传播方向之间的夹角θ为任一值时,碳纳米管薄膜磁化氢等离子体的复介电常数和微波衰减吸收系数公式。在不同条件下数值计算了碳纳米管薄膜中磁化氢等离子体的微波衰减吸收随θ的变化关系。理论结果表明：只要适当调控磁场方向,应用外加静磁场能有效改进碳纳米管氢等离子体的微波衰减吸收性能。通过调节氢等离子体密度、电子有效碰撞频率、外加静磁场的强度和方向,能获得碳纳米管薄膜氢等离子体对某一特定频段微波能的强烈吸收。     

纳米材料的制备、功能化及其器件的性质研究（英文）

一维纳米材料（碳纳米管、纳米线、氧化物纳米带）作为研制纳电子器件理想的材料具有重要的科学意义和应用前景。本工作主要集中在氧化物纳米带、碳纳米管的功能化及其和纳米器件性质研究。     

单壁开口碳纳米管的Randic指数

针对单壁开口碳纳米管的规则性,当给定纳米管的周长(或直径)和长度时,得出了常见的锯齿型开口纳米管和扶手椅型开口纳米管的Randi'c指数的计算公式。并比较出具有相同直径和长度的纳米管,扶手椅型的Randi'c指数较小。