Electrochemical Sensor Based on Polypyrrole for the Detection of Heavy Metals in Aqueous Solutions

摘要

The application of conductive polymers as electrochemical sensors, provides a viable alternative for detection of metal ions, preliminary tests describe the construction of the electrochemical sensor, the electrochemical polymerization was carried out starting from pyrrole monomer, considering as composites electrode component and commercial graphite electrode modified on its surface, from 3M KCl solution as supporting electrolyte, both used as working electrodes. The behavior of the electrode by Cyclic Voltammetry, identified the presence of the polymer through Infrared Spectroscopy FT-IR; it also evaluateed the sensitivity to metal ions in solution of Pb~(2+,) Cu~(2+,) Cd~(2+) and Zn~(2+) with the potentiodynamic polarization technique, also ac impedance measurements were used to evaluate the electrical resistance of the film formed polymer over the electrodes. The characterization of the sensors was carried out by scanning electron microscopy. So far, the best electrochemical performance was observed for Pb~(2+) ion through a better conductivity behavior.