二氧化钛纳米管阵列的二次阳极氧化制备

Fabrication of TiO_2 Nanotube Arrays by a Two-Step Anodic Oxidation

通过二次阳极氧化法在H2O+H3PO4+NH4F+乙二醇电解液中恒电压阳极氧化纯钛片,制备出管结构可控、重复性好的TiO2纳米管阵列。利用FESEM、XRD对TiO2纳米管阵列的形貌、管结构、相组成进行表征。探讨了TiO2纳米管阵列的形成机制,研究阳极氧化电压、电解质水含量与磷酸含量等因素对纳米管的管径、管长的影响。正交实验结果表明,在实验条件下,TiO2纳米管的管径和管长随阳极氧化电压增加而增加;TiO2纳米管管径随水含量0%~4%(体积分数)、磷酸含量的增加而增加,管长随水含量2%~6%(体积分数)、磷酸含量的增加而减少;TiO2纳米管的形貌随氟化铵含量和阳极氧化时间的影响较小。TiO2纳米管阵列在400℃退火3h后,由无定形态转变为锐钛矿相。

A two-step anodic oxidation was used to prepare TiO2 nanotube arrays with controllable tube structure by the isobarically anodization of pure Ti sheet in H2O+H3PO4+NH4F+ ethylene glycol electrolyte. The morphology, tube structure and phase constitution of TiO2 nanotube were investigated by FESEM and XRD. The formation mechanism of TiO2 nanotube arrays were discussed. The effect of applied voltages, water content and phosphoric acid content of electrolyte on the diameter and length of TiO2 nanotube arrays were studied. The result of orthogonal test shows that the diameter and the length of TiO2 nanotube arrays increase with increasing the applied voltages, the diameter of TiO2 nanotube arrays increases with increasing water content (0%~4%) and the phosphoric acid content, the length of TiO2 nanotube arrays decrease with increasing water content (2%~6%) and the phosphoric acid content, the morphology of TiO2 nanotube arrays are little affected by ammonium fluoride content and anodic oxidation time under the experimental conditions. TiO2 nanotubes annealed at 400 ℃ after 3h have a transformation from amorphous to anatase phase.