二氧化钛纳米管的制备改性及其光催化性能研究

发布时间：2018-05-24 01:30

本文选题：TiO_2纳米管 + Cu掺杂　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：二氧化钛(TiO_2)以其物理化学性质稳定,低成本,无毒性,同时其还具有较高的光催化活性和良好的光电化学性能,是一种被广泛关注的半导体材料。然而,由于TiO_2自身较宽的禁带宽度(3.2 eV),限制其在可见光范围的响应。于是有必要对TiO_2纳米管进行掺杂与改性,以期提高其在可见光范围的响应,增加对太阳光的利用率。本文采用电化学阳极氧化制备高度有序TiO_2纳米管,研究了阳极氧化CuTi合金,一步制备Cu-Ti-O纳米管,实现Cu的掺杂;通过直流反应磁控溅射沉积Cu_2O在TiO_2纳米管上,制备Cu_2O-TiO_2纳米管,进行窄禁带半导体修饰改性。甲基橙(MO)是一种常见的染料,其水溶液的脱色效果可以用来衡量光催化降解率,本文对比研究了上述两种改性TiO_2纳米管的光催化性能。采用阳极氧化的方法制备高度有序的TiO_2纳米管阵列薄膜,研究了不同工艺参数对其形貌的影响。主要采用的表征手段是扫描电子显微镜(SEM),探究了环境温度,电压,阳极氧化时间和有机酸添加剂对其形貌的影响,并从机理上进行了解释说明。从而,通过调节制备过程工艺参数,可以对TiO_2纳米管的微观结构和尺寸进行调控。通过阳极氧化CuTi合金,制备了Cu-Ti-O纳米管,实现了Cu掺杂TiO_2纳米管。利用X射线衍射仪(XRD)、X射线光电子能谱(XPS)、紫外可见分光光度计等手段对Cu-Ti-O纳米管进行了表征。通过高压汞灯提供紫外辐照,光催化降解甲基橙溶液,以其降解速率来表征光催化性能。结果表明,Cu-Ti-O的光学吸收带边可以扩展至450 nm,光催化性能较纯TiO_2却没有得到提升。采用直流反应磁控溅射的方法,在TiO_2纳米管表面沉积Cu_2O纳米颗粒,制备出Cu_2O-TiO_2纳米管。利用一系列手段对Cu_2O-TiO_2纳米管进行表征,得到了Cu_2O负载TiO_2纳米管最佳工艺参数,探究了其白光光催化性能。结果表明,最佳Cu_2O沉积条件:溅射功率76 W,溅射压强1.0 Pa,溅射气体比例22:1(Ar:O_2),沉积时间20 s。Cu_2O-TiO_2纳米管的光学吸收带边可以扩展至450 nm以上,在400-600 nm波段上的吸收显著增强。白光辐照下,光催化降解甲基橙溶液,120 min内降解率达到94.4%,性能提升了1.14倍(单一TiO_2纳米管120 min内降解率为44%)。
[Abstract]:Titanium dioxide (TiO2) is a widely concerned semiconductor material due to its stable physical and chemical properties, low cost, non-toxicity, high photocatalytic activity and good photochemical properties. However, due to the wide bandgap of TiO_2 itself, its response in the visible range is limited. Therefore, it is necessary to doping and modifying TiO_2 nanotubes in order to improve their response in visible light range and increase the utilization ratio of solar light. In this paper, highly ordered TiO_2 nanotubes were prepared by electrochemical anodic oxidation. The anodizing of CuTi alloy was studied, and the Cu doping was realized by one-step preparation of Cu-Ti-O nanotubes. Cu_2O-TiO_2 nanotubes were prepared by Cu_2O deposition on TiO_2 nanotubes by DC reactive magnetron sputtering. The narrow gap semiconductor modification was carried out. Methyl Orange (MOO) is a common dye, and its decolorization effect can be used to measure the photocatalytic degradation rate. The photocatalytic properties of the two modified TiO_2 nanotubes were studied in this paper. The highly ordered TiO_2 nanotube array films were prepared by anodic oxidation. The effects of different process parameters on the morphology of the films were investigated. The influence of ambient temperature, voltage, anodizing time and organic acid additive on the morphology of SEM was investigated by means of scanning electron microscope (SEM), and the mechanism was explained. Thus, the microstructure and size of TiO_2 nanotubes can be regulated by adjusting the process parameters. Cu-Ti-O nanotubes were prepared by anodic oxidation of CuTi alloy and Cu doped TiO_2 nanotubes were realized. Cu-Ti-O nanotubes were characterized by X-ray diffractometer X-ray photoelectron spectroscopy (XPS) and UV-Vis spectrophotometer. The photocatalytic degradation of methyl orange solution was carried out by UV irradiation with high pressure mercury lamp, and the photocatalytic activity was characterized by its degradation rate. The results show that the optical absorption band edge of Cu-Ti-O can be extended to 450nm, but the photocatalytic performance of Cu-Ti-O is not improved compared with pure TiO_2. Cu_2O nanoparticles were deposited on the surface of TiO_2 nanotubes by DC reactive magnetron sputtering and Cu_2O-TiO_2 nanotubes were prepared. Cu_2O-TiO_2 nanotubes were characterized by a series of methods, and the optimum technological parameters of Cu_2O loaded TiO_2 nanotubes were obtained, and their white photocatalytic properties were investigated. The results show that the optimal Cu_2O deposition conditions are as follows: sputtering power 76 W, sputtering pressure 1.0 Pa, sputtering gas ratio 22: 1 A: O _ 2. The optical absorption band edge of 20 s.Cu_2O-TiO_2 nanotubes can be extended to more than 450nm, and the absorption at 400-600 nm band is enhanced significantly. Under white light irradiation, the degradation rate of methyl orange solution reached 94. 4% in 120 min, and its performance was improved by 1. 14 times (the degradation rate of single TiO_2 nanotube within 120 min was 44%).
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TQ134.11

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