自持TiO_2纳米管阵列薄膜与TiO_2/FTO透明光电极制备工艺的研究

INVESTIGATION OF THE FABRICATED TECHNOLOGY OF FREE-STANDING TIO_2 NANOTUBE MEMBRANES AND TIO_2/FTO TRANSPARENT PHOTOELECTRODE

利用电化学阳极氧化法,采用三步氧化工艺,成功制备出大面积高度有序、孔洞分布均匀、孔道垂直取向且与金属钛基相分离的自持TiO2纳米管阵列膜。然后将其转移粘接至FTO导电玻璃上,形成高度有序的TiO2/FTO纳米管阵列透明光电极。利用场发射扫描电镜、X射线衍射仪、紫外-可见-近红外分光光度计分别对样品的形貌、晶相结构以及光学特性做了表征。研究表明,由三步阳极氧化工艺制备的自持TiO2纳米管阵列膜,其结构参数(如管径、管长及管壁厚度)在很大范围内可控,将其转移粘结至FTO导电玻璃上能制成多种用途的高质量透明光电极;另外,阳极氧化电压对TiO2纳米管阵列薄膜的光学能隙(Eg)也有较为明显的调制作用。显然,这项新工艺对基于TiO2纳米有序阵列复合结构的有机-无机光电器件的应用研究将是非常有益的。

The large-scale,highly-ordered,vertically-oriented free-standing TiO2 nanotube membranes were fabricated by three-step anodization Ti foils in ethylene glycol containing 0.25w（NH4F）%.Then the as-prepared free-standing membranes were transferred to FTO-coated glass substrates with TiO2 sol,and the transparent TiO2/FTO photoelectrode was obtained after annealing treatment.The morphologies,crystalline phase,optical properties were characterized using FE-SEM,XRD and UV-Vis-NIR spectrophotometer,respectively.To some extent,the structural parameters of the free-standing TiO2 nanotube membranes（inner diameter,nanotube length,and wall thickness）are controllable.After the membranes were transferred onto the FTO-coated glass substrate,we can obtain the high quality and multi-application TiO2/FTO photoelectrode.At the same time,it is found that the optical energy gap（Eg） of TiO2 nanotube membranes could be effectively modulated by different anodic oxidation voltage.Obviously,this work would be beneficial to apply in organic-inorganic photovoltaic devices.