Zn掺杂的TiO₂薄膜的光分解水性能的研究

The Performance of Zn Doped TiO₂ Films in Photo-Electrochemical Water Splitting

本文采用磁控溅射的方法,以金属Ti和ZnO陶瓷为靶材,Ar和O2混合气为工作气体,进行双靶共溅,对沉积的薄膜进行600℃快速退火处理以得到Zn-TiO2薄膜。结果表明,Zn掺杂TiO2引起带隙少量红移。随Zn掺杂元素的含量的增加,Zn-TiO2薄膜的载流子浓度先减小后增加。Zn掺杂引起薄膜的平带电压和光照下薄膜氧化还原反应起始电位值均向负方向移动。Zn掺杂浓度为3.5%时,薄膜光饱和电流密度是不掺杂样品的2.1倍,光分解水性能最佳。

In this work, we prepared Zn-doped TiO2 thin films by magnetron co-sputtering, using Ti metal and ZnO ceramic as targets, and high-purity Ar and O2 as working gases, respectively, followed by rapid thermal annealing at 600?C. It was found that Zn dopants induce a little red shift of TiO2 films band gaps. The carrier densities decreased in the beginning, and then improved with the Zn element concentration increasing. Zn dopant also caused negative shifts of both the flat band potential and the onset potential of redox reaction of films in the light. The results showed that saturated photocurrent density of Zn-doped TiO2 films at 3.5% Zn concentration is 2.1 times as that of un-doped ones, indicating the best water splitting performance.