基于两步法阳极氧化的TiO_2纳米管阵列制备研究

采用低浓度的无机溶剂HF溶液(0.05%,质量分数)对溅射在硅基底上的400 nm钛薄膜进行阳极氧化制备TiO_2纳米管阵列,并利用SEM对制备出的TiO_2纳米管阵列进行表征。实验结果表明,通过优化阳极氧化电压幅值、电压施加方式和氧化时间,均可有效控制纳米管阵列的尺寸和形貌。首先施加0.5 V的低电压28 min,在低浓度的HF溶液中阳极氧化钛薄膜制备TiO_2纳米管阵列,其管径可达120 nm左右。在此基础上,对电压施加方式进行改进,提出两步法施加电压方式,并优化氧化时间,在硅基底钛薄膜上制备出管径为100~270 nm结构紧密有序的TiO_2纳米管阵列,明显优于钛薄膜在有机电解液中氧化制备的管径为70~100 nm的TiO_2纳米管阵列。

Fabrication of TiO2 Nanotube Arrays by Two-step Anodic Oxidation

TiO2 nanotube arrays were fabricated on Si substrate in HF solution with the low concentration of 0.05 wt%. The diameter and the morphology of the TiO2 nanotubes were observed by scanning electronic microscope (SEM). The effects of oxidation voltage and the applying way of voltage on the nanotubes morphology were investigated. The results show that the diameter and the morphology of the TiO2 nanotubes are obviously influenced by the parameters of the oxidation condition. The TiO2 nanotubes with diameters of 120 nm are obtained by applying a voltage of 0.5 V for 28 min in HF solution with the low concentration of 0.05 wt%. The diameter of the nanotubes could be enlarged to a larger range by optimizing the oxidation time. The dense TiO2 nanotubes with diameters ranging from about 100 to 270 nm are fabricated by the two-step anodic oxidation method, which are much better than the TiO2 nanotubes with diameters from about 70 to 100 nm obtained in the organic electrolyte