【作者】 李伟；

【导师】 林海波；

【作者基本信息】 吉林大学 ， 物理化学， 2011， 硕士

【摘要】 近几十年来,电化学科学与技术凭借安全、高效、清洁等优势迅猛崛起,因而电化学工业也得到日新月异的发展。为在相关产业实现高效、优质、无污染、低能耗、低成本的目标,人们对电极材料和电化学反应器提出了更高的要求。在电化学体系中,电极处于核心地位,是影响和实现反应的关键因素。本文从掺杂不同离子(F-、Co2+、Mn2+)的Ti/PbO2电极的制备入手,采用恒电位离子共沉积法制得了性质可控的修饰电极,通过一系列测试技术,如CV、SEM、XRD、XPS等,研究改性后电极的表面形貌、晶体结构、组成、含量及电化学性能等。沉积电位的不同影响F在PbO2电极镀层中的掺杂量,进而影响PbO2的晶型；F的相对含量越高相应的晶体尺寸越小,表现出品体细化、表面平整化的特性；F-还具有抑制氧气析出的作用,相对含量越高,电极的析氧电位越高,应用范围越广,对废水处理等领域中有机物污染物的降解具有重要意义。Co的相对含量随着沉积电位的升高呈现先增后减的趋势；Co相对含量的改变进一步影响电极的表面形貌,由致密的单向生长变成多孔的三维生长；Co2+的掺杂提高了PbO2电极的析氧活性,含量最高时对应的电极的析氧电位最低,此电极对于电合成、有机物降解等工业生产的节能降耗起到重要作用。沉积电位对镀层中PbO2和MnO2的比例没有明显影响,但会改变沉积层的形貌和晶粒尺寸,并影响其电容性质。通过调节电镀液中乙酰丙酮的浓度,可以改变沉积层中PbO2和MnO2的比例,随着浓度的增加,PbO2的比例增加,改变了沉积层的形貌和晶粒尺寸,进而影响电容性能。在0.2 mol·L-1乙酰丙酮溶液中,沉积电位为1.45V时制得的复合电极材料的比电容高达150 F·g-1,电势窗口1.30V。电极表现出来的优良性能和高比电容与Mn2+和Pb2+的复合沉积是密不可分的,有望成功地应用于超级电容器和超级电池中。综上所述,与传统的Ti/PbO2电极相比,这些新型的电极材料无论在理论研究还是在实际应用方面,均有突破,并且为今后的实验工作提供有价值的参考数据,奠定了研究基础。更多还原

【Abstract】 In recent decades, electrochemical science and technology rised rapidly because of safety, high efficiency and cleanliness, thus, the electrochemical industry also progressed with each passing day. For this reason, the requirements of materials and electrochemical reactors are stricter than before, in order to achieve high quality, non-polluting, low power and cost of the relevant industries. In the electrochemical system, the electrode in a pivotal role is the key factor on impacting and implementing reaction. A study on the preparation of Ti/PbO2 electrode doped with different ions (F-,Co2+, Mn2+) was undertaken, and the modified electrodes with controllable nature were obtained by potentiostatic ion co-deposition method. In addition, the surface morphology, crystal structure, composition, content and electrochemical properties were characterized through a series of testing technology, such as CV. SEM, XRD, XPS. etc.The doping content of F in the PbO2 electrode is affected by deposition potential. thereby, crystal form changes with it. The larger the F content is, the smaller the crystal grains is, the F- doping can make the electrode surface become fine and smoothing. Moreover, F- also has the action of inhibiting oxygen evolution. The larger the content of F- is. the higher the oxygen evolution potential is. Therefore, the application range of the PbO2 electrode become wider, the results have important significance for degradation of organic pollutants in the fields of wastewater treatment. The relative content of Co increases first and then decreases with an increasing deposition potential. Its change affects further on the surface morphology of the electrode, which transforms from dense one-way growth into porous three-dimensional growth. Doping with Co improves the oxygen evolution activity of PbO2 electrode. The highest content is corresponding to the lowest oxygen evolution potential. This electrode plays an important role in energy conservation for industrial production such as electrochemical synthesis and degradation of organic compounds.Deposition potential did not significantly affect on the rato of PbO2 and MnO2 in the coatings, but changes the morphology, crystal form and the nature of electrode capacitance. The ratio of the two can be changed by adjusting the concentration of diacetone in the solution.The proportion of PbO2 advanced with an increasing diacetone, which not only influences the morphology and grain size, but also improves the capacitance properties. The highest specific capacitance of the composite electrode obtained at 1.45V in the 0.2M diacetone solution is 150 F/g, and the potential window is 1.30V. It is believed that the prominent performance and high specific capacitance were related to the co-deposition of Mn2+ and Pb2+, making it ideal for supercapacitor and ultrabattery applications.In summary, to compare with the traditional Ti/PbO2 electrode, the new electrode materials have a breakthrough both in theory and in practical applications. R & D work of them provide valuable reference data and lay the foundation for future experimental study.更多还原