Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (11): 2392-2398.doi: 10.3866/PKU.WHXB201309043

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Factors Influencing Hydroxyl Radical Formation in a Photo-Induced Confined Etching System

HU Yan, FANG Qiu-Yan, ZHOU Jian-Zhang, ZHAN Dong-Ping, SHI Kang, TIAN Zhong-Qun, TIAN Zhao-Wu   

  1. State Key Laboratory of Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2013-07-09 Revised:2013-09-04 Published:2013-10-30
  • Contact: ZHOU Jian-Zhang E-mail:jzzhou@xmu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (91023043, 21021002, 91023006).

Abstract:

In this paper, we studied the formation of free ·OH on a TiO2 nanotube array electrode in a photo-induced confined etching system. We used fluorescence spectroscopy, transient photocurrent response, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis to investigate the influence of several key factors, including the applied potential, the illumination time, and the pHvalue. The highest efficiency for the photoelectrocatalytic formation of free ·OH on the TiO2 nanotube array electrode was achieved at an applied potential of 1.0 V (vs a saturated calomel electrode (SCE)); the photoelectrocatalytic generation and consumption of free ·OH quickly approached a steady state in this system, as the confined etching layer formed by ·OH remained stable during illumination. This may allow good control of the etching precision during continuous etching processes. The highest efficiency for the photoelectrocatalytic formation of free ·OH on the TiO2 nanotube array electrode was observed at pH10. The results have an important significance for regulating and optimizing photo-induced confined etching system, which can be used to improve the etching speed or the leveling precision during the planarization of copper.

Key words: Photo-induced confined etching, Free ·OH, Fluorescence detection, Photo-electro-synergistic effect, TiO2 nanotube array

MSC2000: 

  • O649