Published in

American Chemical Society, Analytical Chemistry, 17(82), p. 7135-7140, 2010

DOI: 10.1021/ac101728a

Links

Tools

Export citation

Search in Google Scholar

Formation and Growth of Oxide Layers at Platinum and Gold Nano- and Microelectrodes

Journal article published in 2010 by Claudio Zuliani, Darren A. Walsh, Tia E. Keyes ORCID, Robert J. Forster
This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
  • Must obtain written permission from Editor
  • Must not violate ACS ethical Guidelines
Orange circle
Postprint: archiving restricted
  • Must obtain written permission from Editor
  • Must not violate ACS ethical Guidelines
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

The construction and characterization of platinum and gold disk electrodes with minimum radii of 7 nm (platinum) and 500 nm (gold) is reported. The electrodes were prepared with a micropipet puller using a two step procedure and have been characterized using scanning electron microscopy, scanning electrochemical microscopy, high speed chronoamperometry, and cyclic voltammetry. The formation and growth of platinum and gold oxide layers, on the electrodes at time scales from microseconds to seconds, is reported. Significantly, the apparent microscopic area as determined by forming and subsequently reducing an oxide layer in acidic electrolyte using cyclic voltammetry depends dramatically on the scan rate. While conventional roughness factors between 1.8 and 3 are observed on average for scan rates above 5 V s(-1), the apparent roughness can exceed 30 for scan rates less than 0.5 V s(-1). Chronoamperometry, conducted on the microsecond to millisecond time scale, is used to probe the dynamics of monolayer and multilayer oxide formation as well as the reversibility of the oxide formation and removal. The latter study suggests that (at least for platinum) the growth of the oxide layer proceeds with a lower constant rate after an oxide monolayer is formed.