Glassy carbon electrode activation - A way towards highly active, reproducible and stable electrode surface

Glassy carbon (GC) is one of the most often used carbon materials in laboratory practice. Despite the fact that its electrocatalytic properties are largely surface-state dependent, a standardised procedure for its activation is lacking. This work presents a detailed, systematic investigation of aGC electrode pre-treatment based on potential cycling in a strongly alkaline environment within optimised potential limits. The surface composition was followed by X-ray photoelectron spectroscopy. This allowed determination of the overall elemental surface composition as well as identification of important surface functional groups. Electro-catalytic activity of the activated electrodes was tested by using Fe3+/2+, Fe(CN)(6)(3-/4-) and benzoquinone/hydroquinone couples. A combination of spectroscopic and electrochemical information made it possible to establish a correlation between the electrode's electrocatalytic activity and its surface composition and to identify optimal activation conditions which resulted in a highly active, reproducible and stable electrode surface. It can be concluded that, due to its relative simplicity and efficiency, the present method has the potential to become a standard procedure of GC electrode activation. (C) 2019 Elsevier Ltd. All rights reserved.