Development of a technology for obtaining a multilayer nanoporous aluminium oxide

This paper presents a study in the field of aluminum anodizing in mixed electrolytes. A complex electrolyte containing oxalic, citric and boric acids, as well as isopropanol was used. Mixed anodizing modes were used, such as constant voltage and current modes, with various stationary values. Anodic nanoporous alumina containing a “layered” system was obtained. Nanoporous oxide was examined by scanning electron microscopy (SEM), optical microscopy and XRD. It is shown that the "layers" of aluminum oxide are retained during high-temperature annealing in air. The anodizing technique presented in this work allows us to expand the range of morphology and geometry of nanoporous alumina.