光电催化降解活性蓝染料的研究

以液相沉积法在不锈钢片上沉积TiO2薄膜,以该TiO2/不锈钢片作为光阳极,Pb为阴极,采用单槽反应器和双槽反应器,研究了水中活性蓝染料的光电催化降解行为。结果表明,光电降解有机染料时,外加阳极偏压可提高TiO2薄膜电极的光催化活性。在相同的气氛下,活性蓝在双槽反应器的光电催化反应速率大于单槽反应器的反应速率;利用光电流的大小可以判断反应速率的快慢,本实验光电催化降解效率最大时,溶液的pH=7,阳极偏压为0.6 V,紫外光照射下两槽中通入空气。     

TiO2薄膜光电催化亚甲基蓝的研究

采用溶胶-凝胶-浸渍法在钛基底上制备了TiO2薄膜,以该薄膜为工作电极,石墨作对电极,饱和甘汞电极为参比电极,建立光电催化反应体系,对亚甲基蓝溶液进行了光电催化降解研究。结果表明：当外加偏压1.0 V,热处理温度500℃时,pH为10.2,TiO2薄膜光电催化活性最好,光电催化亚甲基蓝120 min可使其脱色率达64....     

TiO_2光催化甲基橙电化学阻抗法表征的研究

采用溶胶-凝胶法在Al2O3薄膜表面上制备了纳米TiO2光催化薄膜(TiO2/Al2O3),将此薄膜用于光催化降解甲基橙,采用电化学阻抗法分析了TiO2薄膜光电极在甲基橙溶液中暗态、光照、不同光强以及改变阳极偏压时的交流阻抗图谱。结果表明,电化学阻抗谱能够较好的反应光催化、光电催化降解甲基橙的实验过程;并且发现施加阳极偏压可提高薄膜的催化性能,发现0.4 V左右最佳。     

钛基TiO_2纳米管光电催化降解甲基橙

采用阳极氧化法制备了TiO2纳米管,并进行扫描电镜分析。以TiO2纳米管为工作电极,石墨作对电极,对甲基橙溶液进行光电催化降解研究,考察了阳极氧化电压、时间、热处理温度、电解液组成、外加偏压的影响。结果表明,阳极氧化电压为20 V,氧化时间20 min,热处理温度500℃,V(H3PO4)∶V(NH4F)=1∶1,外加偏压为0.6 V时,甲基橙(5 mg/L)经TiO2纳米管光电催化30 min,脱色率达到96.3%。     

钛基TiO_2纳米管光电催化降解甲基橙

采用阳极氧化法制备了TiO2纳米管,并进行扫描电镜分析。以TiO2纳米管为工作电极,石墨作对电极,对甲基橙溶液进行光电催化降解研究,考察了阳极氧化电压、时间、热处理温度、电解液组成、外加偏压的影响。结果表明,阳极氧化电压为20 V,氧化时间20 min,热处理温度500℃,V(H3PO4)∶V(NH4F)=1∶1,外加偏压为0.6 V时,甲基橙(5 mg/L)经TiO2纳米管光电催化30 min,脱色率达到96.3%。     

Ag／TiO2对含酚废水的光电催化降解

以悬浮态Ag/TiO2为光催化剂，网状Ti为电极，以含酚废水为模型化合物，进行三维立体电极光电催化降解有机污染物研究。结果表明，外加阳极偏压可有效提高Ag/TiO2光催化降解反应速度，Ag的质量分数为1．5％时苯酚光电催化降解率达最大值。外加电压对光催化降解反应速度的影响存在双峰效应，     

纳米TiO2膜电极光电催化降解污染物的研究进展

纳米TiO2基薄膜光电催化通过外加偏压阻止光生电子与空穴发生复合以提高光催化的量子效率,并使有机污染物发生深度矿化。本文详细介绍了光电催化的反应机理、TiO2基薄膜电极的制备及提高光电催化效率的主要途径、影响光电催化过程的主要因素等,最后对TiO2光电催化的发展方向进行了展望。     

石墨负载TiO2薄膜电极光电催化降解甲基橙研究

采用溶胶-凝胶法制备石墨负载TiO2薄膜电极，以125W高压汞灯为光源，以负载TiO2薄膜的石墨片为工作电极，铂电极为对电极，饱和甘汞电极为参比电极，建立三电极的光电催化体系，以甲基橙为降解对象．考察了初始浓度、涂敷层数、外加电压、通入空气对甲基橙降解速率的影响。研究表明，石墨是光催化剂良好的载体．外加电压可以促进光催化降解的效率，外加电压2V、涂敷3层、通入空气时对目标物质的降解效果最好。     

二氧化钛薄膜光电催化Cr(Ⅵ)的影响因素

以TiO2薄膜为工作电极,铂网作为辅助电极,甘汞电极为参比电极,进行紫外光光电催化还原Cr(VI),探讨了溶液初始pH值、Cr(VI)初始浓度以及柠檬酸浓度对反应性能的影响。结果表明,在酸性条件下,TiO2对Cr6+离子污染具有显著的光电催化还原消除效果;随着Cr(VI)初始浓度的增加,其光电催化还原反应速率降低;柠檬酸作为空穴捕获剂可有效地捕获光生空穴,在一定浓度范围内,Cr(VI)的光电还原反应速率随柠檬酸浓度的增加而增加。在pH为3、0.6 V偏压、0.006 g柠檬酸条件下,初始浓度为10 mg/L的Cr(VI)反应210 min时,其转化率达到82.19%。     

TiO_2电极制备、表征及光电催化研究

文章采用阳极氧化法制备了TiO2纳米管电极、TiO2膜电极,对其进行了SEM、XRD表征的比较。研究了电化学过程、光解、TiO2纳米管的光催化、TiO2纳米管电极的光电催化对五氯苯酚的降解,研究表明光电催化降解速度最快。此外,TiO2纳米管电极和TiO2膜电极对五氯苯酚的光电催化降解也进行了研究。结果表明,TiO2纳米管电极对五氯苯酚光电催化效果明显好于TiO2膜电极,2h二者的降解率分别为81.5%,69%。     

Photoelectrocatalytic degradation of phenol using a TiO<Subscript>2</Subscript>/Ni thin-film electrode

As a new type of photoelectrode, TiO₂/Ni thin-film electrode was prepared by dip-coating technique. The structural and surface morphology of electrode was examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). Effects of initial phenol concentration, pH value, number of film layers, voltage of electrical bias applied, variation of inorganic salt type and types of dissolved gas on the photoelectrocatalytic (PEC) degradation of phenol using ultraviolet (UV) illuminated TiO₂/Ni thin-film electrode were investigated. The mechanism of PEC degradation of phenol was also studied by analyzing reaction intermediates.     

负载型二氧化钛光电催化降解苯酚废水的反应动力学

采用浸渍提拉法制备发泡镍载二氧化钛薄膜电极，并以其为工作电极，建立三电极光电催化体系，对该体系降解苯酚的动力学进行了研究.考察了反应液初始pH值、反应物初始浓度、催化剂用量、光辐照强度、外加直流偏压值对光电催化反应速率的影响，采用幂指数方程描述反应动力学，得到方程C=C₀exp(-0.5430 C ^-0.4241 ₀ E ^0.2968 Q ^0.5418 I ^0.5877 t).方程计算值与实验值吻合较好，误差基本在15％以内.     

光电协同催化氧化处理饮用水中藻毒素-LR

以TiO2薄膜为光阳极,利用光电协同催化氧化技术降解水中藻毒素-LR,并研究该技术降解藻毒素-LR过程中的各种影响因素。随着阳极偏电压的增加藻毒素的去除率先增加后持平,当阳极偏电压值高于最佳值时,去除率保持不变甚至略有降低。充足的氧源会明显促进降解过程提高了藻毒素的去除率。pH的微小变化会引起去除率的较大波动。高流速的体系使得污染物在反应器中停留时间过短,从而导致其去除率的降低。过低的流速又不利于电极表面的传质过程,同样会降低藻毒素的去除率。在本论文的反应器中,以TiO2/Ti板为光阳极,在阳极偏电压2.5 V、空气环境、pH=8的体系流速为100 mL/min时,对藻毒素的去除率最大,2 h后就可达95%以上。     

不同载体表面负载TiO2薄膜的离子掺杂研究

TiO₂薄膜是解决TiO₂回收的有效方法，缺点是TiO₂活性低，寻找合适的载体以及提高TiO₂薄膜的光催化活性,是TiO₂负载薄膜技术需要解决的核心问题。研究了13种离子对负载在釉面瓷砖、玻璃、陶瓷、钛片、铝片和不锈钢片6种载体上TiO₂薄膜的掺杂，并从界面材料结构、双电层结构等方面讨论了离子掺杂与载体对TiO₂薄膜光催化活性的影响。结果表明，TiO₂薄膜的离子掺杂效果不仅和离子掺杂浓度、种类有关，而且还与载体类型有关。TiO₂薄膜和非金属载体主要形成复合半导体结构，改善掺杂离子对载流子的捕获能力。金属载体与TiO₂薄膜之间主要形成肖特基势垒，有利于电子与空穴的分离。载体与TiO₂薄膜之间形成的界面双电层结构能改变离子捕获中心与TiO₂半导体费米能级间的相对位置，从而提高或降低离子对载流子的捕获能力。     

Photoelectrocatalytic degradation of rhodamine B using Ti/TiO2 electrode prepared by laser calcination method

The method of Ti/TiO₂ photoelectrode prepared by using laser calcination method instead of oven calcination process was introduced. The prepared TiO₂ film was observed with AFM and XRD. Photoelectrocatalytic degradation of rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. The laser power applied in this electrode preparation was also discussed, and it indicated that TiO₂ particle prepared with high laser power was crystallized adequately and the photoelectrocatalytic ability was satisfactory. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. The photoelectrocatalytic oxidation using the Ti/TiO₂ electrode calcinated by laser was compared with that of the electrode calcinated by furnace, and it showed that the reaction rate of RB degradation using the electrode by laser was faster than that by furnace. Additionally, electrochemical impedance spectroscopy (EIS) was performed at the two different photoelectrodes, which verified the higher photocatalytic activity of the laser-treated electrode further.     

Electron conduction in passive films on nickel

The electron conduction properties of the passive film on nickel in acid solution were studied by differential capacitance of nickel electrode in the passive condition, and by redox reactions of the Fe²⁺/Fe³⁺ and Q/H₂Q systems. A large capacitance value of the passive electrode, which is possibly comparable to that of the double layer, can be ascribed to the space charge capacitance in the passive film which is highly nonstoichiometric. The redox reaction currents of these systems may be sustained by tunnelling of charge carriers through the space charge layer in the passive film, if it can be accepted that the tunnel effect commences when the electric field strength in the space charge layer is of the order of 10⁶ V/cm. Consequently, the passive film can not be an insulator, at least in acid solutions.     

纳米TiO_2膜电极的制备及其电催化性能

采用溶胶-凝胶法制备TiO2溶胶,以钛酸丁酯为前驱物和二乙醇胺为催化剂,研究了不同条件下(水量、溶剂量、催化剂量、温度)TiO2溶胶的制备过程,得出了最佳工艺条件,采用此溶胶制备了纳米膜电极,用XRD、拉曼光谱进行表征,用循环伏安法分析了其电催化性能,结果表明其电催化性质与晶型有关。     

Approach to a pulse photoelectrocatalytic process for the degradation of organic pollutants

Ag–TiO₂ composite film was supported on indium–tin oxide glass (ITO) by a dip‐coating and subsequent photodeposition procedure. The composite film was employed as the photoanode for photoelectrocatalytic (PEC) degradation of Acid Orange II. The degradation efficiency for the PEC process on the Ag–TiO₂/ITO electrode with a 0.8 V anodic bias is significantly higher than that for a photocatalytic process on Ag–TiO₂/ITO film or for a PEC process on a neat TiO₂/ITO photoanode. A new PEC technology with a pulse anodic bias was also proposed in order to solve the problem of the loss of deposited Ag from the Ag–TiO₂/ITO. It was found that the PEC process with a 4.2 V pulse anodic bias could much more efficiently degrade Acid Orange II than that with a constant anodic bias of 0.8 V or 4.2 V. Moreover, when the duration of the open and close circuit time was identical, the treatment efficiency was observed to be optimal. Copyright © 2003 Society of Chemical Industry