钛基金属氧化物电极降解有机污染物的研究

发布时间：2018-03-09 05:35

  本文选题：电催化氧化　切入点：钛基金属氧化物　出处：《苏州科技学院》2015年硕士论文　论文类型：学位论文

【摘要】：制备了四种阳极:Ti/SnO_2-Sb电极、Ti/SnO_2-Sb/PbO_2电极、Ti/SnO_2-Sb/MnO_2电极和Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极,分别用线性伏安扫描(LSV)、扫描电镜(SEM)、X射线衍射(XRD)、电极加速寿命等方法对电极性能进行了表征,并以苯酚为目标污染物,考察了几种电极的电降解性能。另外,还将Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极用于降解实际印染废水。研究结果如下:(1)比较了Ti/SnO_2-Sb、Ti/SnO_2-Sb/PbO_2和Ti/SnO_2-Sb/MnO_2三种电极对苯酚的电降解性能。研究结果表明:3种电极对苯酚降解反应均遵循一级反应动力学规律。当电流密度为10 mA/cm2,降解初始浓度为100 mg/L苯酚溶液时,Ti/SnO_2-Sb,Ti/SnO_2-Sb/PbO_2,和Ti/SnO_2-Sb/MnO_2电极对苯酚去除率分别为99.4%、98.2%、63.6%,COD去除率分别为80.1%、76.8%、40%。其中Ti/SnO_2-Sb/PbO_2电极由于具有最长的加速寿命(41 h),较高的析氧电位(1.78V)和较好的电催化活性被认为是降解苯酚的最佳电极。(2)为了进一步提高Ti/SnO_2-Sb/PbO_2电极的使用寿命,在电极中间层中引入了二氧化钛纳米管,制备了Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极。采用阳极氧化法分别在乙二醇电解液体系和丙三醇电解液体系中制备了二氧化钛纳米管。研究结果表明:以乙二醇电解液体系制备的纳米管管口为圆形,且随着阳极氧化电压的增大,纳米管的管径和管壁厚度增大。以丙三醇电解液体系制备的纳米管管口为螺线性,且管子呈条纹型的竹节状。450℃煅烧后二氧化钛纳米管的晶型由无定型状态转化为锐钛型。(3)以丙三醇体系制备的TiO_2-NTs为基体制备了Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极,并考察了该电极对苯酚的降解效果。研究结果表明:Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极与Ti/SnO_2-Sb/PbO_2电极相比,电极表面颗粒细小致密、拥有更长的加速寿命(77.5h)、更高的析氧电位(1.93V)和更好的降解效果(苯酚去除率99.3%,COD去除率86.5%),对苯酚的降解符合一级动力学规律。利用异丙醇作为羟基自由基捕获剂,3h后苯酚的降解率仅为69%,较未加入时的去除率大大下降,说明苯酚的降解为羟基自由基原理。(4)将Ti/TiO_2-NTs/SnO_2-Sb/PbO_2电极用于处理实际印染废水,考察了电流密度、pH、电解时间对印染废水中COD和氨氮的影响。研究结果表明,降解印染废水的最佳电流密度为20 mA/cm2,最佳p H为7。COD和氨氮浓度随电解时间的延长逐渐降低,降解3h时均达到《纺织染整工业水污染物排放标准》GB4287-2012的间接排放标准。
[Abstract]:Four kinds of anode: ti / SnO _ 2-Sb / Ti / SnO _ 2-S _ bO _ 2-S _ bO _ 2-S _ bO _ 2 electrode and Ti / SnO _ 2-SbO _ 2-Mn _ 2O _ 2 electrode and Ti/TiO_2-NTs/SnO_2-Sb/PbO_2 electrode were prepared. The electrode properties were characterized by linear voltammetry scanning, scanning electron microscope (SEM), X-ray diffraction (XRD), accelerated lifetime of the electrode, and phenol as the target pollutant, respectively. The electrodegradation properties of several kinds of electrodes were investigated. The Ti/TiO_2-NTs/SnO_2-Sb/PbO_2 electrode is also used to degrade the actual printing and dyeing wastewater. The results are as follows: 1) the electrochemical degradation properties of the three kinds of Ti / SnO _ 2-SbO _ 2-SbO _ 2-SbO _ 2-S _ bO _ 2 and Ti/SnO_2-Sb/MnO_2 electrodes for phenol degradation are compared. The results show that the degradation of phenol at the three kinds of electrodes follows the first-order reaction kinetics. Rule: when the current density is 10 Ma / cm ~ 2 and the initial concentration of degradation is 100 mg/L phenol solution, Ti- / SnO _ 2-SbO _ 2-SbO _ 2-SbO _ 2-SbO _ 2-SbO _ 2 and Ti/SnO_2-Sb/MnO_2 electrode are 99.498. 22% and 63.6% respectively. The Ti/SnO_2-Sb/PbO_2 electrode has the longest accelerated lifetime of 41 h and higher oxygen evolution rate. In order to further improve the service life of Ti/SnO_2-Sb/PbO_2 electrode, the potential 1.78V) and the better electrocatalytic activity are considered as the best electrode for phenol degradation. Titanium dioxide nanotubes were introduced into the middle layer of the electrode. Ti/TiO_2-NTs/SnO_2-Sb/PbO_2 electrode was prepared. Titanium dioxide nanotubes were prepared in ethylene glycol electrolyte system and glycerol electrolyte system by anodizing method. The diameter and wall thickness of nanotubes increased with the increase of anodizing voltage. After calcined at 450 鈩，

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