(1. 中南大學(xué)粉末冶金國家重點實驗室，長沙 410083；
2. 中南大學(xué)湘雅醫(yī)院，長沙 410008)
摘 要: 基于TiO2納米管薄膜的廣泛應(yīng)用前景，采用陽極氧化的方法制備高度規(guī)則排列的TiO2納米管陣列，研究外加電壓、陽極氧化時間、電解液(NH4F+乙二醇)濃度、電解液體系對納米管陣列生長特性的影響。結(jié)果表明：隨著外加電壓從10 V增大到30 V，納米管的管徑和管壁逐漸由22 nm和4.5 nm分別增至82 nm和10 nm，而納米管密度由2240 μm-2降至200 μm-2。納米管陣列出現(xiàn)的臨界陽極氧化時間為5 min，且隨著氧化時間延長，納米管的長度隨之增加，當(dāng)氧化時間增至2 h時，納米管長度增至4 μm，此后，納米管長度不再增長。在含F(xiàn)-的有機(jī)電解液體系中可制備規(guī)則的納米管陣列，當(dāng)電解液(NH4F+乙二醇)濃度增加到0.2mol/L后，出現(xiàn)清晰的納米管管狀結(jié)構(gòu)，這是由于F-和乙二醇的存在對于TiO2納米管陣列的形成具有至關(guān)重要的作用，F(xiàn)-與Ti4+形成的[TiF6]2-能延緩鈦箔陽極的氧化進(jìn)程，促使鈦箔表面形成微孔；而乙二醇則有助于提高電解液的黏度，降低F－的擴(kuò)散速率，保證TiO2納米管陣列的穩(wěn)定生長。
關(guān)鍵字: TiO2；陽極氧化法；納米管陣列；生長特性
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Xiangya Hospital, Changsha 410083, China）
Abstract:Based on the wide promising application of TiO2 nanotube films,highly ordered TiO2 nanotube arrays were prepared by anodization method.The effects of applied voltages, anodization time, electrolyte (NH4F+ethylene glycol) concentration, electrolyte system on the growing characteristics of TiO2 nanotube arrays were studied. The results show that the nanotube diameter and wall thickness increase from 22 nm and 4.5 nm to 82 nm and 10 nm, respectively, and the nanotube density decreases from 2240 to 200 μm-2as the applied voltage increasing from 10 V to 30 V. The critical oxidation time of appearance of nanotube array is 5 min. The length of nanotubes increases with the oxidation time, and when the oxidation time is 2 h, the length of nanotubes increases to 4 μm and no more longer. The clear nanotube interface appears when the electrolyte (NH4F+ethylene glycol) concentration increases to 0.2 mol/L. The reason is that the existence of F- and ethylene glycol is very important for the formation of TiO2 nanotube. The formation of [TiF6]2- by the reaction of F- and Ti4+ can retard the oxidization process of Ti foil and help Ti foil produce micropores on its surface. The ethylene glycol is beneficial to increase the electrolyte viscosity and decrease the F- diffusion rate. Therefore, the uniform growth of TiO2 nanotube array can be guaranteed.
Key words: TiO2; anodization; nanotube array; growing characteristics
