Electrochemical oxidation and reduction processes at diamond electrodes of varying phase purity

✍ Scribed by Foord, John ;Hu, Jing Ping

• Book ID: 105364068
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 304 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200671117

✦ Synopsis

Abstract

Diamond electrodes were prepared by MWCVD, using varying methane‐to‐hydrogen feedstock ratios to form both micro‐ and nano‐crystalline samples. Although Raman spectroscopy indicated substantial concentrations of non‐diamond carbon in the nanodiamond forms, XPS and ELS measurements confirm that the area‐averaged concentration of such material in the outer layers is very low. Nonetheless, pronounced electrochemical signatures associated with disordered sp^2^ carbon phases are detected, at sites which are highly aggregated in the grain boundaries. Potential cycling in nitric acid presents an effective route for the complete removal of sp^2^ carbon material from the electrodes, but this then leads to the formation, of what electrochemically, are completely inactive nanodiamond phases. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)