导　　师： 张巨生

学科专业： 081702

授予学位： 硕士

作　　者： ;

机构地区： 哈尔滨工业大学

摘　　要： TiO2作为一种宽禁带的半导体材料,在光催化领域和太阳能转换等方面有着巨大的应用价值,其制备方法、催化机理和物理化学性质的研究一直是众多学者关注的焦点。采用无模板剂的路线,通过改进制备方法和制备条件,合成了一系列不同晶相和形貌的TiO2纳米材料,通过测试表征,研究了晶相组成和表面修饰对其光催化活性的影响。 采用胶溶法在低温条件下通过调节酸胶溶的浓度,制备出具有高度分散的金红石相TiO2/(R-TiO2/)梭形纳米棒、不同比例金红石相/(R/)//锐钛矿相/(A/)的TiO2纳米粒子及锐钛矿相/(A-TiO2/)纳米颗粒。并采用光辐照将Au3+离子还原成Au纳米粒子原位沉积在不同晶相组成的TiO2表面。通过测试其对亚甲基蓝的降解率,研究TiO2不同晶相组成与形貌对Au-TiO2复合材料光催化活性的影响,结果表明:在TiO2表面负载Au后,其光催化活性均有明显提高。活性提高顺序为:锐钛矿含量较高的Au-TiO2 /(主A相Au-TiO2/)> A相Au-TiO2>金红石相含量较高的Au-TiO2/(主R相Au-TiO2/) > R相Au-TiO2。当Au与TiO2的负载比例为0.08/%时,其光催化活性由70.77/%提高到97.8/%。 采用溶剂热法以酞酸丁酯、异丙醇和HF为原料制备出具有较高催化性能的/(001/)晶面TiO2。研究了钛用量、HF反应量、水热反应温度及时间对/(001/)晶面TiO2的制备和光催化活性的影响。研究发现在30 ml的水热釜中,当钛浓度为0.15 g//ml、40/%的HF加入量为0.6 ml时,在180℃条件下水热反应24 h所制备的TiO2所含/(001/)晶面最多,光催化活性最高。且负载Au后,紫外光照射90 min时其催化活性由38.68/%提高至65.82/%。 As a broad forbidden-band semiconductor, titania /(TiO2/) has significant applications in solar energy conversion, photocatalysis and photoelectronic devices. Therefore, the preparation methodology, catalysis mechanism and physicochemical properties of TiO2 have attracted a lot attention by many researchers. Without any template, TiO2 nanoparticles with different crystal phases and morphologies have been synthesized by improving the preparation methods and optimizing the preparation conditions. The effects of crystal phase and surface modification on the photocatalytic activities of TiO2 nanoparticles are tested and analyzed. By controlling the concentration of acid peptizator, highly dispersed rutile TiO2 /(R-TiO2/) shuttle-like nanorods, TiO2 nanoparticles with different ratios of rutile phase and anatase phase /(R//A-TiO2/), and anatase TiO2 /(A-TiO2/) nanoparticles are prepared through a low-temperature sol-gel phase transfer technique. Meanwhile, Au nanoparticles are in situ deposited on TiO2 nanoparticles by an optical radiation of Au3+ solution. Effect of Au-TiO2 nanoparticles on the degradation rate of Methylene blue is tested to investigate the influences of crystal phase and morphology of TiO2 nanoparticles on the photocatalytic activities of Au-TiO2 nanocomposites. It is found that the photocatalytic activity of TiO2 can be obviously enhanced by surface decoration of Au nanoparticles. The photocatalytic activity of the prepared materials can be ranked as: Au-R//A-TiO2/(with more anatase phase/)> A-Au-TiO2> Au-R//A-TiO2 /(with more rutile phase/)> R-Au-TiO2. With 0.08 mol/% Au decorated, the photocatalytic efficiency of Au-R//A-TiO2 /(with more rutile phase/) can be as high as 97.8/%, which is an obvious improvement as compared with that of R//A-TiO2 /(with more rutile phase/) /(70.77/%/). /(001/)-rich TiO2 with high photocatalytic activity are also prepared by a solvothermal method, using butyl phthalate, isoproponal and HF as raw materials. The effects of raw material amount, temperature and reaction time on the preparation and photocatalytic activity of /(001/)-rich TiO2 are studied. Research indicates that in a 30-ml hydrothermal reactor charged with butyl phthalate concentration of 0.15 g//ml and 0.6 ml of 40/% HF, /(001/)-rich TiO2 can be obtained at 180 oC for 24 h. Notably, this /(001/)-rich TiO2 displays a high photocatalytic activity. Deposited with Au nanoparticles, the photocatalytic efficiency of TiO2 has improved from 38.68/% to 65.82/% with UV radiafion for 90 min.

关 键 词： 纳米复合材料 晶面 光催化性能

分 类 号： [TB383.1]

领　　域： [一般工业技术]