Gold Nanoparticles Partially Embedded in Ultrathin Anodic Alumina Films

• Published in: Journal of physical chemistry. C Vol. 113; no. 8; pp. 3105 - 3109
• Main Authors: Mardare, Andrei Ionut, Borodin, Sergiy, Wieck, Andreas Dirk, Rohwerder, Michael, Hassel, Achim Walter
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.02.2009
• Subjects: C: Nanops and Nanostructures
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp806979g

Gold nanoparticles with diameters ranging from 3.2 to 9.7 nm were prepared on an ultrathin anodic aluminum film by means of molecular beam deposition. Coverages ranging from 17.9% to 48.5% and the subsequent anodic anodization behavior were studied. Further oxide growth does not completely cover the gold nanoparticles but takes place preferentially under the particles with a surprisingly low kinetic hindrance. The gold nanoparticles are electrically isolated from the substrate as demonstrated by the absence of electrocatalytic reactions on the gold surface. A strong surface charge phenomenon is observed, which increases with increasing gold coverage that yields an increase of the capacity up to the minimum potential required for further oxide formation.