【作者】 阮修莉；

【导师】 全燮；

【作者基本信息】 大连理工大学 ， 环境科学， 2005， 硕士

【摘要】 本文采用阳极氧化法制备了TiO₂纳米管电极,SEM图像表明:TiO₂纳米管顶部开口,定向排列整齐,分布均匀,其管径范围在30-70nm。XRD结果证明,阳极氧化法制备的TiO₂纳米管为无定型晶型,经煅烧后为具有良好光催化活性的锐钛矿型。DRS分析结果表明,TiO₂纳米管电极的起始吸收边带发生了蓝移,禁带宽度为3.32eV。 以PCP为目标物考察了TiO₂纳米管电极在石英玻璃反应器内的光电催化氧化性能及影响因素,系统分析了PCP光电催化的主要影响因素,如外加偏压、溶液初始pH值、Na2SO₄浓度、光强及TiO₂纳米管电极面积,并与同样采用阳极氧化法制备的TiO₂膜电极处理PCP的降解效果和光转换效率进行了比较。本文还考察了TiO₂纳米管电极的稳定性。对TiO₂纳米管电极光电催化PCP过程产物也进行了推断。实验结果表明,使用TiO₂纳米管电极的PCP光催化氧化与电化学作用存在明显的协同作用。结果表明,增加外加偏压、Na₂SO₄浓度以及酸性溶液对PCP的光电催化是有利的。在完全相同的实验条件下,TiO₂纳米管电极处理PCP的动力学常数是TiO₂膜电极1.4倍,光转换效率是其的1.3倍。10次的TiO₂纳米管电极处理PCP的平行实验证明了电极良好的稳定性,只有3.3%的偏差。TiO₂纳米管电极光电催化PCP过程产物为少量的四氯酚、醌和一些简单酸类物质。 通过浸渍法对TiO₂纳米管电极进行Zn²⁺、Fe³⁺、Cu²⁺离子的掺杂改性。从SEM及XRD的结果表明,金属离子掺杂后的TiO₂纳米管电极依然保持了良好的表面形态及锐钛矿晶型,但DRS分析表明,进行掺杂的TiO₂纳米管电极的光学性质有着不同程度的改变,禁带宽度分别为3.37eV、3.14eV、2.86eV。更多还原

【Abstract】 TiO₂ nanotubes electrode is fabricated by anodic oxidation method. SEM images indicat that the top-opened TiO₂ nanotubes are well aligned and organized into high-density uniform arrays, with diameter ranging in size from 30 to 70 nm. The XRD patterns show that the sample fabricated by anodic oxidation is amorphous without being annealed. As the 500°C annealed sample crystallized in the anatase phase, which is in good photocatalytic activity. The initial absorbance edge is blue-shift and the energy band gap is 3.32eV.In quartz glass reactor, the photoelectrocatalytic degradation of PCP in aqueous solutions as well as the effect factors such as bias potential, the initial pH value in solution, concentration of Na₂SO₄, light intensity and the area of the TiO₂ nanotubes electrode was investigated. The PCP degradation first-order kinetic constant and photo-conversion efficiency using TiO₂ nanotubes electrode are compared to that of using TiO₂ film electrode （prepared by anodic oxidation） in the same conditions. The stability of TiO₂ nanotubes electrode is also evaluated. The interim-products are also deduced. The result indicates that the photocatalysis and the electrochemical process have a significant synergic effect on the degradation of PCP. The photoelectrocatalysis of PCP is enhanced when increasing bias potential, Na₂SO₄ concentration and in acidic solution. This result indicated that the kinetic constant of PEC degradation of PCP and photo-conversion efficiency on TiO₂ nanotubes electrode is 1.4,1.3higher than that of TiO₂ film electrode in the same condition respectively. The results of the 10 repeated experiments for photoelectrocatalytic degradation of PCP in 2h show that the degradation efficiencies are rather stable with the deviation only 3.3%. Little tetrachlorophenol （TetraCP）, quinone and some other simple inorganic acids are the course products.Zn²+, Fe³+ and Cu²+ are doped on TiO₂ nanotubes electrode using dipping method. Both SEM and XRD results show doped TiO₂ nanotubes electrode remain tube-like structure and anatase. However, DRS displays doped TiO₂ nanotubes electrodes’ initial absorbance edges shift in different degree. Energy band gaps are 3.37eV、3.14eV、 2.86eV respectively.更多还原