Improved growth rate of anodized TiO2 nanotube arrays under reduced pressure field and light illumination

• Published in: Science bulletin (Beijing) 2017-03, Vol.62 (5), p.332-338
• Main Authors: Huo, Shuyao, Xu, Zhen, Yin, Min, Yu, Dongliang, Chen, Xiaoyuan, Wang, Hui, Tian, Li, Li, Dongdong
• Format: Article
• Language: English
• Subjects: Light stimulation; Photoelectrochemical properties; Reduced pressure field; TiO2 nanotube anodization
• ISSN: 2095-9273
• DOI: 10.1016/j.scib.2017.01.036

The one-dimensional titanium oxide （TiO2） nanotubes （TONT） can be rationally fabricated in the fluoridecontaining electrolyte by electrochemical anodization. The high-speed growth of TONT for elongated nanotubes is highly desirable because the undesirable chemical etching will induce ＂nanograss＂ on the top of nanotubes and restrain the continued elongation of nanotubes. Herein, the external fields were employed to accelerate the growth of TONTs and obtain the elongated TONT arrays. A growth rate up to 18 μm/h was achieved under the presence of reduced pressure （0.07 MPa） and UV light （365 nm） stimulation. The generation of longer nanotube arrays could be attributed to the applied fields, which facilitate timely gas pumping out and induce chemical equilibrium shift forward. The TONT films obtained under different parameters were subsequently employed as anodes for photoelectrochemical （PEC） water splitting. The photocurrent （at 0 V vs Ag/AgCI） of TONT electrode obtained under external fields represented a 50% enhancement compared with the pbotoanode produced by the conventional method.