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1、 . . . 硕士学位论文论文题目: 一种镀制二氧化铅电极的新型镀液及其成核机理作者： 汉水 指导教师： 童少平教授 学科专业： 应用化学 所在学院： 化学工程学院 提交日期：_2013年4月7日_ . . . . A Thesis Submitted to Zhejiang University of Technologyfor the Degree of MasterA NOVEL BATH FOR PREPARATION OF LEAD DIOXIDE ELECTRODE AND ITS NUCLEATION MECHANISMSubmitted byLiu HanshuiSupervi
2、sed byProf. Shaoping TongCollege of Chemical Engineering Zhejiang University of Technology，Hangzhou，ChinaApril, 2014工业大学学位论文原创性声明本人重声明：所提交的学位论文是本人在导师的指导下，独立进行研究工作所取得的研究成果。除文中已经加以标注引用的容外，本论文不包含其他个人或集体已经发表或撰写过的研究成果，也不含为获得工业大学或其它教育机构的学位证书而使用过的材料。对本文的研究作出重要贡献的个人和集体，均已在文中以明确方式标明。本人承担本声明的法律责任。作者签名： 日期： 年
3、月 日学位论文使用授权书本学位论文作者完全了解学校有关保留、使用学位论文的规定，同意学校保留并向国家有关部门或机构送交论文的复印件和电子版，允许论文被查阅和借阅。本人授权工业大学可以将本学位论文的全部或部分容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本学位论文。本学位论文属于1、，在_年解密后适用本授权书。2、不。(请在以上相应方框打“”)作者签名： 日期： 年 月 日导师签名： 日期： 年 月 日一种镀制二氧化铅电极的新型镀液及其成核机理摘要 本文首先综述了电催化氧化技术在水处理方面的应用和不同种类电催化电极的制备和应用，重点讨论了不同镀液对二氧化铅电极性能的影响。
4、基于传统镀液制备二氧化铅电极的不足，本文提出了一种新型镀液，并对其的成核机制进行了较为系统的研究。首先，在传统镀液（硝酸铅和硝酸溶液，适量的添加剂，记为bath-）和新型镀液 (乙酸铅和氨基磺酸，适量的添加剂，记为bath-) 中分别镀制钛基二氧化铅电极 (分别记为PbO2-和PbO2-)。X射线衍射（XRD）分析结果表明，两个电极的表面物相均为-PbO2，但是PbO2-具有更小的晶粒。通过计算得到PbO2-的平均晶粒大小为6.6 nm，PbO2-的平均晶粒大小为50.7 nm。SEM分析结果显示PbO2-表面更加平整致密，晶粒更细化，这和XRD结果一致。利用这两个二氧化铅电极降解对氯苯酚的结
5、果表明，PbO2-对对氯苯酚及其化学耗氧化量（COD）有更高的去除能力。两种电极在0.5mol/L硫酸溶液中的电化学阻抗谱分析（EIS）结果表明，PbO2-有更大的双电层电容和更低的电荷转移电阻。耐腐蚀性测试结果表明了PbO2-有更高的耐腐蚀性。其次，通过循环伏安法（CV）和计时电流法（CA）法研究了两种镀液中二氧化铅在预制备钛基体上的成核机制。CV测试结果表明，二氧化铅在bath-中有更高的成核过电位，并且随扫描次数递增逐渐减小，最后趋于相对稳定。利用Scharifker-Hill 模型解析了两种镀液的CA测试结果，表明在bath-中PbO2在预制备钛基体的成核更偏向瞬时成核。在瞬时成核条件
6、下，电沉积能得到更细的晶粒，这也与前面XRD和SEM的分析结果相一致。然后，在bath-中，研究了主盐浓度、阳极电位及常见镀液添加剂对二氧化铅在铂基体上成核机制的影响。结果表明，二氧化铅的成核随主盐浓度增大逐渐偏向瞬时成核，在主盐浓度低于0.05mol/L时，二氧化铅成核基本不受阳极电位的影响，在较高主盐浓度时随阳极电位增大，二氧化铅成核逐渐偏向瞬时成核。F-、CeO2能提高二氧化铅的电沉积速率，使成核偏向瞬时成核；聚四氟乙烯（PTFE）乳液的加入几乎对二氧化铅的成核机制几乎没有影响，十二烷基苯磺酸钠（LAS）会明显增大二氧化铅电沉积时的成核过电位，成核也偏向瞬时成核，SEM结果显示晶粒变细，
7、成核量增大。最后，结合前面的结果，预研了电化学氧化和臭氧氧化预处理酸性化工废水的效能。结果发现bath-制备的二氧化铅电极对酸性化工废水的电化学氧化比臭氧氧化有更好的预处理效能。关键词：电沉积，二氧化铅电极，镀液，成核，Scharifker-Hills模型A NOVEL BATH FOR PREPARATION OF LEAD DIOXIDE ELECTRODE AND ITS NUCLEATION MECHANISMABSTRACTThe application of electrochemical oxidation technology in water treatment and th
8、e properties of different electrodes are reviewed. The emphasis of this work is the preparation of high performance PbO2 electrode. Owing to the shortages of the traditional bath, a novel bath was proposed, and the nucleation mechanism of PbO2 was also investigated.Firstly, two PbO2 electrodes ( not
9、ed as PbO2- and PbO2-) electrodes were prepared in traditional bath (Pb(NO3)2, HNO3, some additives, which was noted as bath-) and novel environment-friendly bath (Pb(CH3COO)2, H2NSO3H, some additives, which was noted as bath-), respectively. The results of X-ray diffraction (XRD) showed that the cr
10、ystalline phases of the two electrodes were both -PbO2, but the XRD of PbO2- had bigger main diffraction half peak width. The average grain size of PbO2- was calculated to be 6.6 nm by Scherrer equation, while the average grain size of PbO2- was 50.7 nm. Scanning electronic microscopy (SEM) revealed
11、 that PbO2- had a more compact and uniform surface compared with PbO2- , which well agreed with XRD results. The degradation of p-chlorophenol indicated that the electrochemical oxidative performance of PbO2- was better than that of PbO2-. Electrochemical impedance spectroscopy (EIS) study showed th
12、at PbO2- had higher double layer capacitance and lower charge transfer resistance for oxygen evolution in 0.5 molL-1 sulfuric acid than PbO2-. The lifetime test showed that PbO2- had higher corrosion resistance.Secondly, the nucleation mechanism of PbO2 on the pretreated Ti subtract was investigated
13、 by cyclic voltammograms (CV) and chronoamperometry (CA) in two different baths. CV test showed PbO2 had higher nucleation overpotential in bath-, and the nucleation overpotential gradually decreased with the increasing number of CV scanning, finally tending to be relatively stable. Using Scharifker
14、-Hills model to analyze CA test results, which showed the nucleation process of PbO2 in bath- was more inclined to the three-dimensional instantaneous nucleation mode according to Scharifker-Hills model than that in bath-. It is more easily to get finer grain in instantaneous nucleation, which is we
15、ll confirmed the results obtained by X-ray Diffraction (XRD) and scanning electron microscope (SEM) tests.Finally, the influences of anode potential, main salt concentration and different additives on mechanism of PbO2 nucleation were studied. The results showed PbO2 nucleation gradually clined to instantaneous nucleation as the increasing concentration of main salt. PbO2 nucleation was not affected by the anode potential in lo
