Preparation of porous anodic aluminum oxide in water-deficient electrolytes

Well-ordered large-pore anodic aluminum oxide membranes were one-step prepared in water-deficient electrolytes using ethanol as main solvent. The effects of water content, electrolyte concentration and solvent types were studied with the help of SEM. The results showed that the involved electrochemical anodization and corrosion could be controlled by changing the amount of water added in the electrolyte, and the pores of the AAO membranes could be made in a controlled manner within a long reaction time. The pores were hexagonally ordered and narrowly diameter-distributed ((95 +/- 13) nm) in comparison with those produced with normal electrolytes using water as the sole solvent ((95 +/- 30) nm). With this method, the applied anodizing voltage spans a wider range, and so does the tuning of the pore diameters. This approach can broaden the application of the AAO templates in the fabrication and processing of nanoarrays and porous materials