预掺杂法制备Au/TiO2纳米管薄膜及其光电性能研究

提出了一种在TiO2纳米管(TNT)阵列形成之前将贵金属纳米粒子作为掺杂剂引入的预掺杂法,该方法可以有效地避免传统掺杂方法中贵金属粒子堵塞纳米管管口的问题。首先采用磁控溅射法在FTO导电玻璃基底上制备Au/Ti双层金属薄膜,然后将上层金属Ti膜进行电化学阳极氧化,退火后即可获得Au/TNT电极薄膜。利用扫描电子显微镜、X射线衍射和X射线光电子能谱分别对Au/TNT电极薄膜的微观结构和组成成分进行了观察和表征,确定Au元素存在于复合薄膜中的同时,还发现位于薄膜底部的Au纳米颗粒,经阳极氧化和退火后,扩散到了上层的TNT阵列薄膜中。测试发现,可见光照射下,Au/TNT电极薄膜的光电流密度和光催化降解率分别约为纯TNT阵列薄膜的2.0和1.3倍。因此,采用预掺杂法制备光电性能优良的Au/TNT电极薄膜是可行有效的。

Preparation and photoelectric properties of Au/TiO2 nanotube film by a pre-doping method

A pre-doping method in which Au nanoparticles(NPs) were introduced as dopants before the formation of a TiO2 nanotube(TNT) array was proposed in this paper. This method was intended to decorate a TNT array film with Au nanoparticles(Au/TNT), which effectively avoided the problem of blocking the top of the nanotubes by noble metal particles by post-doping methods. Au/TNT array film was fabricated by anodizing the double Au/Ti metal film, which was obtained by successive magnetron sputtering of Au and Ti films onto FTO substrates. Scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the microstructure and components of the Au/TNT nanotubes array, which revealed the existence of Au in composite film, meanwhile discovered the diffusion of Au NPs from the bottom of the film into the upper TNT array film after anodization and annealing. It was tested that the photocurrent value and the photocatalytic efficiency of the Au/TNT electrode were about 2.0 and 1.3 times of that of the pure TNT electrode, respectively. Therefore, it is obvious that the pre-doping method is feasible and effective for fabricating a high-photocatalytic-efficient Au/TNT electrode.