Study of the composite electrodes carbon-polyvinyl chloride and carbon-polyvinyl chloride/Nafion by ex situ and in situ methods

摘要

The electrochemical response of the composite electrodes carbon-polyvinyl chloride and carbon-polyvinyl chloride/Nafion was studied in various aqueous electrolytes. Ex situ studies using AFM, SEM and EDS showed that after prolonged electrochemical pretreatment by repetitive potential cycling between -0.3 and 1.3 V in 0.1 m H_2SO_4,changes occur to the surface composition, topography and morphology of the electrodes. In situ studies with electrochemical techniques using electrodes retreated with carbon-polyvinyl chloride and modified with rutheniumphenanthroline complex exhibited electrochemical activity of redox systems, as well as selectivity in the determination of dopamine in a solution containing excess ascorbic acid.