Photocurrent Enhancement for Ti-Doped Fe2O3 Thin Film Photoanodes by an In Situ Solid-State Reaction Method
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- 作者：Chunhui Miao ; Tongfei Shi ; Guoping Xu ; Shulin Ji ; Changhui Ye
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2013
- 出版时间：February 27, 2013
- 年：2013
- 卷：5
- 期：4
- 页码：1310-1316
- 全文大小：572K
- 年卷期：v.5,no.4(February 27, 2013)
- ISSN：1944-8252
文摘
In this work, a higher concentration of Ti ions are incorporated into hydrothermally grown Ti-doped (2.2% by atomic ratio) micro-nanostructured hematite films by an in situ solid-state reaction method. The doping concentration is improved from 2.2% to 19.7% after the in situ solid-state reaction. X-ray absorption analysis indicates the substitution of Fe ions by Ti ions, without the generation of Fe2+ defects. Photoelectrochemical impedance spectroscopy reveals the dramatic improvement of the electrical conductivity of the hematite film after the in situ solid-state reaction. As a consequence, the photocurrent density increases 8-fold (from 0.15 mA/cm2 to 1.2 mA/cm2), and it further increases up to 1.5 mA/cm2 with the adsorption of Co ions. Our findings demonstrate that the in situ solid-state reaction is an effective method to increase the doping level of Ti ions in hematite films with the retention of the micro-nanostructure of the films and enhance the photocurrent.