2024-03-29T13:37:02Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/682402022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Self-ordered Porous Alumina Fabricated via Phosphonic Acid AnodizingAkiya, ShuntaKikuchi, TatsuyaNatsui, ShungoSakaguchi, NorihitoSuzuki, Ryosuke O.AnodizingPorous AluminaPhosphonic AcidSelf-orderingNanostructure430Self-ordered periodic porous alumina with an undiscovered cell diameter was fabricated via electrochemical anodizing in a new electrolyte, phosphonic acid (H3PO3). High-purity aluminum plates were anodized in phosphonic acid solution under various operating conditions of voltage, temperature, concentration, and anodizing time. Phosphonic acid anodizing at 150-180 V caused the self-ordering behavior of porous alumina, and an ideal honeycomb nanostructure measuring 370-440 nm in cell diameter was successfully fabricated on the aluminum substrate. Conversely, disordered porous alumina grew at below 140 V, and anodizing at above 190 V caused local thickening due to oxide burning. Two-step phosphonic acid anodizing allows the fabrication of high aspect ratio ordered porous alumina. HPO32 anions originated from the electrolyte were incorporated into the porous oxide during anodizing. Consequently, a double-layered porous alumina consisting of a thick outer layer containing incorporated HPO32 anions, and a thin inner layer without anions was constructed via phosphonic acid anodizing.ElsevierJournal Articleapplication/pdfhttp://hdl.handle.net/2115/68240https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/68240/1/Phosphonic.pdf0013-4686Electrochimica acta1904714792016-02-01enginfo:doi/10.1016/j.electacta.2015.12.162© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/author