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2911320 
Journal Article 
Facile preparation of active glassy carbon electrodes with activated carbon and organic solvents 
Ranganathan, S; Kuo, TC; Mccreery, RL 
1999 
Yes 
Analytical Chemistry
ISSN: 0003-2700
EISSN: 1520-6882 
71 
16 
3574-3580 
English 
WOS:000082075100037 
Pretreatment of glassy carbon (GC) electrodes with 2-propanol, acetonitrile, or cyclohexane had a significant effect on electrode kinetics, adsorption, and capacitance. Reagent grade solvents slowed electron transfer rates for dopamine, ascorbic acid, Fe(3+/2+), and Fe(CN)6(3-/4-) and decreased adsorption of anthraquinone-2,6-disulfonate (AQDS) and methylene blue (MB). However, if activated carbon (AC) was present in the solvent during pretreatment, the result was increased electron transfer rates and adsorption for several commonly studied redox systems. The large surface area of AC acts as a 'getter' for solvent impurities and for species desorbed from the GC surface, leading to a carbon electrode surface with higher capacitance, higher adsorption of AQDS and MB, and faster electron-transfer rates for Fe(CN)6(3-/4-), dopamine, and ascorbic acid. In addition, the treated surfaces were more reproducible, and aged electrodes were reactivated by AC in 2-propanol. The results imply that large, polar organic impurities are present on the polished GC surface which are removed by the combination of an organic solvent and activated carbon. These impurities contain oxygen detectable by XPS and appear to be weakly catalytic toward the Fe(3+/2+) redox system.