Electrosynthesis and electrochemical characterisation of polypyrrole in 1-hexyl-2,3-dimethylimidazolium tetrafluoroborate and 1,2-dimethylimidazolium methylsulfate. Application to the detection of copper in aqueous solutions

摘要

ABSTRACT Electropolymerisation of pyrrole was carried out in the presence of two ionic liquids: 1-hexyl-2,3-dimethylimidazolium tetrafluoroborate and 1,2-dimethylimidazolium methylsulfate. Electrochemical technics such as cyclic voltammetry, chronoamperometry and chronopotentiometry were used. The obtained PPy films were characterised by electrostability, electroactivity and electrochemical impedance spectroscopy. After electrosynthesis and electrocharacterisation, the PPy electrosynthesised in the presence of 1,2-dimethylimidazolium methylsulfate was applied to the detection of Cu2+ in aqueous solutions, using Differential Pulse Anodic Stripping Voltammetry. We obtained a detection limit of 32 mg L?1 for a sensitivity of 0.02 μA cm?2?μM?1 and a linear range of 3–8?mM.