纳米ZnO电极的制备及光电催化降解苯酚的研究

采用溶胶-凝胶法制备纳米ZnO粉体,通过X射线衍射和透射电镜研究了纳米ZnO粉体的结构和形貌。XRD和TEM测试表明,所制备的ZnO粉体,具有六方晶系纤锌矿结构,晶粒平均线性粒径约为30 nm。以涂覆法制备纳米ZnO电极,考察外加电压、电极间距离和支持电解质浓度对苯酚降解率的影响。结果表明:在室温(20℃)下,外加电压2.0 V、电极间距离为0.60 cm、支持电解质Na2SO4的浓度为0.070 mol/L时,苯酚的降解率可达70%。动力学研究表明,苯酚降解反应为一级反应。     

光电催化降解双酚A的研究

采用sol—gel法制备TiO2薄膜光电极,以该电极为工作电极,铂丝为对电极,饱和甘汞电极为参比电极,对双酚A的光电催化降解进行了研究,结果表明：该电极具有“型半导体的特征行为．外加偏压为＋0．8V、pH=4,0．88mmol／L的H2O2中,对初始浓度为0．22mmol／L的双酚A溶液光照180min,降解率达70．24％,讨论了氧的存在、外加偏压、双酚A浓度和pH值等因素对光电催化反应的影响。     

Modification of TiO2 nanotubes arrays by CdS and their photoelectrocatalytic hydrogen generation properties

In order to realize hydrogen generation under visible light, novel CdS/TiO2 nanotubes arrays are developed by electrochemical anodizaUon of Ti in 0.15 mol/L NHTF ＋ 0.08 mol/L H2C2O4 electrolyte. The diameter of the nanotube is 80-100 nm and the length is approximately 550 nm. The CdS nano-particles are deposited on the TiO2 nanotubes arrays by chemical bath deposition （CBD） in the ammonia-thiourea system. A 300 W Xe lamp is used as the light source, CdS/TiO2 nanotube arrays are used as the photoanode with the application of 1.0 V bath voltage, and 0.1 mol/L Na2S ＋ 0.04 mol/L Na2SO3 solution is used as the electrolyte, then the rate of photoelectrocatalytic hydrogen generation is 245.4 μL/（h·cm^2）. This opens new perspectives for photoelectrocatalytic hydrogen generation by using CdS/TiO2 nanotubes arrays.     

电解质影响光电耦合处理效率的试验研究

实验研究了不同电解质对光电催化剂阳极的影响,采用分光光度法测定了光电催化降解率随时间的变化.结果表明,电解质对光电催化反应是有影响的,起反应的是阴离子而不是阳离子,电解质的存在能提高光电催化效率,与SO42-、Cl-相比,CO32-的存在去除率较高.     

苯酚的TiO2薄膜光电催化降解及反应产物的分布

采用ＴｉＯ２薄膜光电催化法,借助于ＨＰＬＣ测试技术研究了苯酚的降解及氧化产物的 分布。研究结果表明,苯酚的降解以及中间产物的分布与苯酚的外加电压、ＴｉＯ２薄膜电极的制膜条件、样品处理量等因素有关,在适当的光电催化条件下,可以将苯酚全部分解为无毒无害的低分子化合物。     

Fabrication of visible-light responsive S-F-codoped TiO<Subscript>2</Subscript> nanotubes

Fabrication and S-F-codoping of TiO2 nanotubes were carried out by a one-step electrochemical anodization process to extend the photoresponse of TiO2 to the visible-light region. The prepared samples were annealed in air and detected by SEM, XRD, XPS and UV-vis DRS spectrophotometer. The results showed that the average tube diameter of the nanotubes was 150 nm and the average tube length was 400 nm. The doped TiO2 nanotubes exhibited strong absorption in visible-light region. Photoelectrocatalytic degradation efficiency of 4-CP over S-F-codoped TiO2 nanotubes was 39.7% higher than that of only-F-doped sample. Moreover, sulfur and fluorine codoped into substitutional sites of TiO2 had been proven to be indispensable for strong response and high photocatalytic activity under visible light, as assessed by XPS.     

Fabrication of visible-light responsive S-F-codoped TiO_2 nanotubes

Fabrication and S-F-codoping of TiO2 nanotubes were carried out by a one-step electrochemical ano-dization process to extend the photoresponse of TiO2 to the visible-light region. The prepared samples were annealed in air and detected by SEM,XRD,XPS and UV-vis DRS spectrophotometer. The results showed that the average tube diameter of the nanotubes was 150 nm and the average tube length was 400 nm. The doped TiO2 nanotubes exhibited strong absorption in visible-light region. Photoelectro-catalytic degradation efficiency of 4-CP over S-F-codoped TiO2 nanotubes was 39.7% higher than that of only-F-doped sample. Moreover,sulfur and fluorine codoped into substitutional sites of TiO2 had been proven to be indispensable for strong response and high photocatalytic activity under visible light,as assessed by XPS.     

用藻类生长抑制试验研究光电催化水中五氯酚毒性特征

采用96h藻类生长抑制试验考查了光电催化水中五氯酚过程中以及不同降解条件下的急性毒性变化规律．结果表明，光电催化去除五氯酚水溶液毒性的能力高于直接光解、电氧化；光电催化降解五氯酚的过程中溶液毒性逐步降低，反应2h后，溶液的毒性降低到初始毒性的11％．反应最佳条件为电解质Na2SO4浓度0．01mol／L，pH在7左右．     

化学需氧量(COD)快速测定新方法研究进展

化学需氧量是反映水体有机污染程度的综合性指标, 是我国控制污染总量排放的重要水质参数, 但其常用的标准测定方法具有操作烦琐、分析时间长、成本高且二次污染严重的缺点. 本文综述了近年来提出的新型化学需氧量测定方法, 特别是基于TiO₂纳米管阵列的光电催化法, 这些方法以羟基自由基为主要氧化剂与有机物发生反应为基础, 向着快速、准确、低耗、无二次污染、在线监测的全新方向发展, 为环境中有机污染物的监测与控制提供了一个全新的理念与思路.     

多酸基纳米复合材料的制备及性能研究进展

杂多酸基纳米复合材料在光电催化、生物传感器件等方面有较好的应用前景,其合成方法简单、环保,催化性能良好。利用杂多酸同时作为包覆剂、还原剂和链接剂制备银纳米粒子@多酸-碳纳米管三元纳米复合材料,该材料可以提高修饰电极的抗甲醇干扰性,且具有很高的电催化氧气还原反应(ORR)活性。利用原位还原方法同时还原金属离子与氧化石墨,制备出包括金、铂、钯纳米粒子等贵金属纳米粒子@多酸-石墨烯以及银纳米网@多酸-石墨烯三元纳米复合材料,可作为良好的生物传感材料和燃料电池电极材料。利用高温NH3处理制备银纳米粒子@多酸-氮掺杂石墨炔三元纳米复合材料,可实现无金属高活性ORR电催化。