The influence of electrolyte composition on the growth of nanoporous anodic alumina. (1st September 2016)

• Record Type: Journal Article
• Authors: Stępniowski, Wojciech J.; Moneta, Marcin; Norek, Małgorzata; Michalska-Domańska, Marta; Scarpellini, Alice; Salerno, Marco
• Is Part Of: Electrochimica acta. Volume 211(2016)
• Page Start: 453
• Page End: 460
• Publication Date: 2016-09-01
• Subjects: Anodization -- Self-organization -- Alumina -- Nanopores -- Ionic mobility; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.06.076
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Anodization of aluminum in mixed sulfuric-chromic acid electrolytes was performed. Increase of chromic acid molar fraction decreases the current density and oxide growth rate. Interpore distance increases with the molar fraction of chromic acid. Pores density decreases with the increase of the molar fraction of chromic acid. Logarithm of current density and oxide growth rate was a quadratic function of voltage. Abstract: Aluminum was anodized in mixtures of aqueous sulfuric and chromic acid in different ratios, with overall concentration of 1.0 M. It was found that the logarithm of current density (and consequently, oxide growth rate) is a square function of the anodizing voltage. Moreover, the barrier layer thickness at the pores bottom was found to increase exponentially with the voltage, and increased as well with the fraction of chromic acid in the electrolyte. Additionally, interpore distance of anodic aluminum oxide, formed at the same voltage, was found to increase exponentially with the molar fraction of the chromic acid. Altogether, the high impact of the composition of the electrolyte on the morphological features of the nanoporous arrays is revealed.