自组织TiO_2纳米管阵列的制备及形成机理

Fabrication and formation mechanism of self-organized TiO_2 nanotube arrays

采用电化学阳极氧化法,在纯Ti表面一步制得原位生长的自组织TiO2纳米管阵列。采用扫描电镜（SEM）、X射线光电子能谱（XPS）、紫外？可见光漫反射吸收光谱（UV-visDRS）对煅烧后样品进行表征,并探讨纳米管阵列的形成机理。结果表明,在优化的制备参数条件下,所得TiO2纳米管排列整齐,平均管径约为150nm,平均管长约为400nm,且对400～700nm可见光有较大吸收。XPS分析发现,0.35%（摩尔分数）的F原子掺杂进入TiO2晶格中。可见光催化降解染料AO7的结果表明,673K煅烧的F-TiO2纳米管对AO7的去除率达到37.2%。

Self-organized TiO2 nanotube arrays were fabricated by a one-step electrochemical anodization process on a Ti sheet.The prepared samples were annealed in air and detected by SEM,XPS and UV-vis DRS spectrophotometry.And the possible formation mechanism was presented.The results show that the well ordered TiO2 nanotube arrays with the average tube diameter of 150 nm and the average tube length of 400 nm were fabricated under optimized electrolyte and oxidation conditions.The TiO2 nanotubes exhibit strong absorption in visible-light region of 400-700 nm.The fluorine with an molar fraction of 0.35% is doped into TiO2 nanotubes,as evidenced by XPS.The removal efficiency of AO7 by the F-TiO2 nanotube arrays annealed at 673 K reaches 37.2 % under visible light irradiation.