氧化钛纳米管阵列的表面聚集控制及光电化学特性

Control of Surface Morphology of Highly Ordered TiO2 Nanotube Arrays and the Photoelectrochemical Properties

摘要:

采用阳极氧化法在有机介质中制备垂直排列的厚度达百微米的TiO2纳米管阵列，重点考察TiO2纳米管表面形貌特性的控制，以期从微观修饰角度来提高TiO2纳米管阵列膜的光电化学性能；在此基础上，考察不同处理条件下的TiO2纳米管阵列膜的光电化学特性。实验结果表明：采用无水乙醇作为超声液并结合二次蒸馏水进行漂洗能彻底清除纳米管表面聚集堵塞部分，得到清洁、规整有序的纳米管阵列表面，且不破坏纳米管阵列膜的最佳超声振动时间为20~30 s。在对纳米管阵列的表面形貌特性进行控制后，采用一步阳极氧化法+无水乙醇超声制备的样品经500 ℃退火在全谱段的光转换效率达到1.48 %，证实对纳米管阵列的表面形貌特性实施控制能有效提高其光电化学性能。

Abstract:

Vertically oriented TiO2 nanotube arrays having lengths up to 100 microns were prepares by anodic oxidation in organic electrolytes. Control of surface morphology of TiO2 nanotube arrays were surveyed principally, in order to improve the photoelectrochemical property of TiO2 nanotube array from a point of view of microstructure modification; based on these results, the photoelectrochemical properties of the nanotube arrays electrodes with different operation condition were evaluated. The results show that the surface collective block section can be removed entirely by ultrasonic cleaning in ethyl alcohol and the followed rinsing with double distilled water. The clean, regular and highly ordered nanotube arrays surface are obtained with an optimal ultrasonic duration 20-30 s. The as-prepared nanotube-array samples by single step anodic oxidation plus ultrasonic cleaning in ethyl alcohol with another 500 oC annealing show a remarkable photoconversion efficiency of 1.48% under full-spectrum illumination. It is believed that the control of surface morphology may be profitable for the improvement of the photoelectrochemical properties of TiO2 nanotube array.