Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (03): 341-344.doi: 10.3866/PKU.WHXB20060317

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Study on Removal of the Barrier between Al Substrate and Porous Anodic Alumina by Electrochemical Approach

XU Guo-Rong; REN Feng-Lian; SI Shi-Hui; YI Qing-Feng   

  1. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China; College of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, P. R. China
  • Received:2005-07-19 Revised:2005-08-29 Published:2006-03-10
  • Contact: REN Feng-Lian

Abstract: An electrochemical method to remove barrier of porous anodic alumina (PAA) is presented. The barrier of PAA was dissolved by electrolysis in a three-electrode cell with PAA as cathode, Pt as anode and Ag/AgCl as reference electrode in neutral potassium chloride solution. The effects of time, temperature and potential on removal of barrier were investigated. The surface morphologies of the PAA before and after removal of barrier were characterized by SEM. Prussian blue (PB) modified electrode was prepared by a simple electroless deposition in PAA. The electrochemical activity of the Prussian blue modified PAA electrode was investigated by cyclic voltammetry. The results showed that the cyclic voltammogram of PAA exhibited an anodic peak at -0.4 V (vs Ag/AgCl) after electrolyzed for a period of time. The Prussian blue modified PAA electrode exhibited two reversible redox couples resulting from Fe3+/Fe2+ and [Fe(CN)6]3-/[Fe(CN)6]4- transitions in the film. With temperature rising and potential lowering, the speed to produce alkali in PAA rose and the time required to dissolve barrier reduced. At the same time, higher temperature and lower potential could also cause local excess erosion of template. The proper temperature was below 15 ℃. After electrolyzed for 900 s at -1.8 V(vs Ag/AgCl) and 5 ℃, the barrier of PAA could be removed without broadening diameter of pore. Electrochemical method can remove barrier of PAA easily by controlling proper potential, temperature and time.

Key words: Porous anodic alumina, Electrolysis, Barrier layer, Electrochemistry, Alkali