The Decomposition Mechanism of Titania Film with Nanotube Structure
The ordered nanochannel-array of anodic titanium oxide (ATO) is formed on the electro-polished titanium substrate. This reproducible procedure of long-range ordered nanochannel ATO retains 170 nm films in length. The process is deduced by electrochemically and thermodynamically; from high defect structure of porous ATO and small sizing of decomposing TiO2 cluster on the surfaces. In this study, ATO with 68.2% porosity is discomposed at 581 °C under oxygen partial pressure of 4×10-9 atm. The pore of ATO has wall thickness of 25 nm with density of 8×109 per cm2 under 1.2 vol.% hydrofluoric acid (HF) and 10 vol.% sulfuric acid (H2SO4) electrolyte for 90 seconds of 20 V of applied potential. The pore size is 100 nm in diameter and uniformly distributed with 120 nm pore-to pore distance in between.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
C. C. Chen et al., "The Decomposition Mechanism of Titania Film with Nanotube Structure", Advanced Materials Research, Vols. 189-193, pp. 2660-2664, 2011