【作者】 郭婷；

【导师】 孙彦平；

【作者基本信息】 太原理工大学 ， 应用化学， 2002， 硕士

【摘要】 本论文通过综述了大量半导体多相光催化氧化研究文献，找到了制约光电催化的三个关键问题，并针对催化剂的表征问题，提出了现有光催化剂表征上的一些不足之处。 针对这些问题，文中采用了交流阻抗图谱法研究半导体多相光催化系统。实验中运用普林斯顿电化学仪器公司的M273A恒电位仪和M1025频响仪（FRD）及配套软件Powersine测量并分析了TiO₂半导体光催化剂在暗态、不同波长光源及改变阳极偏压下，苯酚和草酸两种体系下的TiO₂交流阻抗图谱（EIS图谱），并从体系交流阻抗变化角度讨论了光源的波长大小、偏压的高低及光的强弱对苯酚光催化和光电催化过程的影响。并在随后进行的部分苯酚降解动力学验证实验中得到了一致的结论。 实验中采用等效电路法处理交流阻抗数据，在系统分析了半导体与溶液界面特性，半导体电极过程特点的基础上，提出了两种TiO₂半导体光电极系统的等效电路模型，其CDC代码分别为：模型ⅠR（RC）（RQ）；模型ⅡR（R[CQ]）。通过对大量不同实验结果的分析，得出模型Ⅰ为本实验体系更合理的等效电路模型。此外，文中还进一步运用EquiVcrt软件对EIS图谱进行解析拟合，计算出半导体材料能带结构的参数，初步建立起了交流阻抗图谱法表征TiO₂光催化剂的新方法。在此基础上，找到了一些对半导体催化剂光催化活性有重大影响意义的因素，并提出了一些提高TiO₂光催化活性的途径。更多还原

【Abstract】 According to a great deal of papers on TiO2 photoeletrocatalysis of waster water degradation, three vital problems which limited the industrialization of photoelectrocatalysic process were put forward in this paper, and some defects on the current characterization of photo-catalyst were also put forward.Aimed at solving the problems, the semiconductor heterogeneous photocatalystic system was studied by the AC Impedance method. The AC Impedance spectra of the TiO2 semiconductor-photocatalyst in the system was detected and analyzed by a Potentiostat(M273A) and a Frequency Spores Detector (M1025) with its relevant powersine software under conditions of having no lights , light with various wavelengths and changed anodic bias, moreover studied the influence of the wavelength , bias and light intensity on the photo-catalysis in the photoelectrocatalysic process of phenol on the aspect of changes of impedance. The results of the following experiments of phenol degradation were identical to the former conclusions.The AC Impedance data were dealt with by the way of Equivalent Circuit. Two kinds of equivalent circuit models of TiO2 semiconductor-electrode system were put forward, which Model I CDC code is R(RC)(RQ) and Model II CDC code is R(R[CQ]), respectively . Herecompared with plenty of simulated results of different experiments, Model I was thought to be the better one. In addition, by using the EquiVcrt software to analyze and simulate the EIS, we calculated these parameters of semiconductor Energy-band Structure and set up a new way of AC Impedance Spectra to characterize the TiO2 photo-catalyst. Factors influencing the activity of semiconductor catalyst were found so as to improve TiO2 photo-catalyst activity.更多还原