TiO2制备条件对光催化氧化活性的影响

半导体光催化剂,如ＴｉＯ２,在紫外光照射下,生成具有强氧化还原活性的电子和空穴,可使许多有机物降解为ＣＯ２和Ｈ２Ｏ,用于处理工业废水具有成本低,无二次污染等优点,是一种很有应用前景的废水催理方法［１,２］．制备高活性的ＴｉＯ２光催化剂是这种过程在处理...     

邻苯二甲酸酯类增塑剂降解研究进展

邻苯二甲酸酯(PAEs)被广泛用于增塑剂行业。近年的研究表明邻苯二甲酸酯具有环境激素的作用,由此引起的环境问题得到世界的普遍关注。在概括介绍邻苯二甲酸酯类增塑剂的种类、结构以及其对环境和人类的危害的基础上,论述了近年来在邻苯二甲酸酯类化合物的降解方面所取得的最新进展,重点讨论并比较了邻苯二甲酸酯的光解和生物降解,指出了目前邻苯二甲酸酯光解和生物降解研究的局限及今后的发展方向。     

UV/草酸高铁铵/H2O2 体系光降解碱性品红研究

研究了用UV／草酸高铁铵／H2O2体系光降解一种碱性阳离子染料—碱性品红．考察了初始pH、H2O2浓度、草酸高铁铵浓度、碱性品红浓度对碱性品红降解率的影响．试验结果表明：碱性品红降解的最佳初始pH为1．60—2．20，最佳初始H2O2浓度为10．0mmol／L；草酸高铁铵的浓度在0．1～1．0mmol／L时，碱性品红的降解率随浓度的增大而增大；高于1．0mmol／L时，则降解率相差不大；碱性品红的初始浓度增大，降解率减小，而实际降解的浓度则增加；碱性品红的浓度在低和高时，降解动力学过程不一致：随降解的进行，碱性品红在可见光区的吸收峰迅速消失，而降解过程中形成的中间产物吸收峰却消失很慢．     

UV/Fenton处理三唑磷农药废水

对UV／Fenton氧化降解模拟三唑磷农药废水进行实验研究．通过测定废水COD_(cr)的变化,考察 [Fe~(2 )]／[H_2O_2],H_2O_2投加量、pH值和初始浓度等因素对三唑磷废水处理效果的影响．结果表明,[Fe~(2 )]／ [H_2O_2]=1:20,H_2O_2为理论投加量Q_(th),pH值为5～7时,光解效果较佳,反应速率常数在0．03 min~(-1)以上,COD_(cr)去除率达到90％．对光解过程的分析表明,三唑磷农药废水的UV／Fenton催化降解过程符合拟一级反应动力学模式．     

射频溅射法和电弧离子镀法制备的纳米TiO2薄膜性能比较

采用射频磁控溅射法和电弧离子镀法制备了纳米TiO2薄膜,并利用XRD、UV-VIS、AFM及通过亲水性和光催化实验对两种方法制备的TiO2薄膜进行了对比表征.结果表明,磁控溅射法的薄膜生长速率只有电弧离子镀法的1/30;前者仅需较低的退火温度就能形成完善的锐钛矿结构;虽然两者有相近的紫外吸收边,但是前者有较大的紫外吸收;磁控溅射法制备的TiO2薄膜表面呈现针状晶结构和具有较大的比表面积;在暗室中保存5 h后,磁控溅射法制备的TiO2膜水的接触角恢复到1°,而后者达到20°;对于光催化降解苯酚,前者有较大的降解率.     

AN EXAMINATION OF THE INFLUENCE OF STABILIZERS ON THE PHOTOCHEMICAL STABILITY OF DISPERSE DYES

There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can be involved for all kinds of dyes. To enhance the photostability of the commonly used disperse dyes, a series of tests on the ef-fect of variable stabilizers on the photodegradation rate of nine representative disperse dyes werecarried out both in ethyl acetate solution and on cellulose acetate film. A moderate light sourceemitting above 300 nm was adopted in this study to simulate the photofading under practical appli-cations. The results show that, in solution, 2,2,6,6-tetramethyl-piperidine is the most effectivegeneral stabilizer for all the tested dyes, but on cellulose film, nickel diethyl-dithiocarbamateshows the greatest general protecting effect, and a synergistic effect is observed for special combina-tions of stabilizers.     

煤基光敏剂对薄膜降解性能的影响

通过户外曝晒自然老化和室内人工加速老化降解实验研究了XUS系列煤基光敏剂对薄膜光降解性能的影响。结果表明煤基光敏刺对薄膜的光降解有较好的催化作用，三种煤基光敏剂的催化活性顺序为：XUS-TF〉XUS-H〉XUS-T。改变煤基光敏剂的类型和添加量可以调节薄膜的光降解速度。煤基光敏刺的光催化活性与煤结构有关。     

Research of Inclusion Complexation of 4,4＇-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.     

用光化学方法去除废水中的有害有机物和金属

研究了一些有机物，如丙酮，酚，染料和茶皂角甙的光催化降解，结果表明：酚的降解与文献报导的情况基本相同，在催化剂TiO2的作用下，紫外光能有效降解纺织厂的印染废水中的染料；金属化合物对光降解反应具有很大影响；还首次试验了用光催化原理消除茶皂甙中有毒溶血素的方法。