【作者】 张志娟；

【导师】 郑敏；

【作者基本信息】 苏州大学 ， 纺织化学与染整工程， 2010， 硕士

【摘要】 本文将晶体缺陷理论与纳米材料的制备相结合,设计一种制备新型双空位触媒氧化锌的方法制备金属-非金属共掺杂纳米ZnO,并来探究氧化锌中缺陷在催化中的作用。研究了制备过程中影响共掺杂纳米ZnO性能的各种因素,通过X射线衍射(XRD)、透射电镜(TEM)、扫描电镜(SEM)、红外光谱(IR)对粉体进行了表征。研究了该类材料的热催化性能和光催化降解性能,并分别对其热催化性能和该催化剂降解亚甲基蓝溶液的催化性能进行了评价,从而确定了制备N-Ce共掺杂ZnO光催化剂的最佳条件。主要研究工作和成果如下:(1)通过实验得出爆燃法制备出高性能氮铈共掺杂纳米ZnO双空位触媒。(2)当硝酸铈的掺杂量为1%、环境温度为750℃、燃烧时间为15s时所得到的粉体综合性能最好,平均粒度为30nm,晶相与标准立方相ZnO衍射峰完全一致,没有其他杂相出现,铈掺入量为0.91%,颜色为均匀的粉色。(3)通过对不同添加方式、混合不同量的氮-铈共掺杂物、不同升温速度等因素的研究发现:当先溶解高氯酸铵,再混合3%氮-铈共掺杂氧化锌催化高氯酸铵(AP)时其热催化性能最好,同时探讨了热催化分解的机理。(4)通过对煅烧温度、硝酸铈的掺杂比例、共掺杂物的浓度、溶液初始pH值、亚甲基蓝的初始浓度、光源、是否通氧等影响因素的研究,发现煅烧温度在700℃,硝酸铈的掺杂比例在1%,共掺杂物的浓度为1.5g/L,溶液pH=9,亚甲基蓝初始浓度为10mg/L,光源为300W通氧的条件下催化降解率最好,在30min内降解率可达到100%。(5)通过对热催化性能和光催化性能的研究发现,空位和电子在催化的过程起了相当重要的作用。通过本文介绍的制备方法可以得到一种高效、低成本的氮铈共掺杂纳米Zn0催化剂该催化剂具有特殊的结构。在催化高氯酸铵和亚甲基蓝水溶液过程中使用该催化剂,可以大大提高催化效率。更多还原

【Abstract】 Physical and chemical properties of crystal materials have sensitive structure.different from the ideal crystal, any real crystals have a certain degree of structural defects which is crystal defects, and crystal defect type, quantity and its law of motion will have tremendous impact on many properties.This article will combine crystal defect theory and preparation of nano-materials to design a new dual-space preparation of zinc oxide catalyst for metal - nonmetal doped nano-ZnO, meanwhile to explore the defects in zinc oxide’s role in catalysis. XRD, FTIR, SEM, TEM and XPS were used to characterize the properties of the as-synthesized amples. its catalytic and Photocatalystic were studied and evaluated,so confirm the optimum technology.The experimental results show that perfect pink powders with standard cubic ZnO crystal phase are obtained under 750℃when the Ce(NO3)3 doping ratio is 1% and the calcining time is 15s.The average primary granularity of the as-synthsized sample is about 30 nm estimated according to Scherrer Equation. The analysises of XPS indicates that the concentrantion of Ce-doped in the sample is 0.91%.Adding different ways, mixing different amounts of N-Ce codoped materials, heating rate were studied, the results show that dissolved ammonium perchlorate at first, then mixed with 3% ammonium perchlorate can get the best performance of its thermal catalytic.Meanwhile explore the mechanism of the thermal catalytic decomposition of ammonium perchlorate.Through the calcination temperature and doping ratio of cerium nitrate, a total dopant concentration, initial solution pH, initial concentration of methylene blue, light source, whether pass oxygen et al influencing factors researching ,the result show the optimum technology is: calcination temperature : 700℃, the doping ratio of cerium nitrate :1%, codoped concentration : 1.5g/L, solution pH = 9, the initial concentration of methylene blue :10mg/L, light source :300W, pass oxygen, and in th 30min the catalytic degradation rate can reach 100%Through the study of the thermal catalytic properties and photocatalytic properties found that: vacancies and electrons in the process of catalytic played an important role.Through the preparation methods described in this article can be an efficient, low-cost N-Ce codoped nano-ZnO. In catalytic ammonium perchlorate and methylene blue solution used in the course of the catalyst, can greatly improve the catalytic efficiency.更多还原