Enhancement of electric properties of polypyrrole by copper electrodeposition

Polypyrrole films (0.2–1.0 μm thick) were electrosynthetized in organic media by potentiodynamic electropolymerization on silicon surfaces. To improve the electronic conductivity of the polypyrrole films, elemental copper was electrodeposited directly on the film surface by simple electrolysis from a copper chloride bath. Copper electrodeposited onto the surface of the polypyrrole film was characterized by X‐ray diffraction and consisted only of Cu fcc phase. The presence of copper on the PPy surface did not greatly affect the overall electronic conductivity of the material. However, immersion of polypyrrole films in Cu 2+ solution for a period of time caused Cu 2+ ions to enter the polypyrrole matrix. The reduction of the Cu 2+ after insertion into the polypyrrole template formed a polypyrrole/Cu composite with high electrical conductivity; this conductivity was higher for longer steeping (immersion) time. Raman spectroscopy shows much greater peak intensities when copper was present in the polypyrrole matrix. Scanning electron microscopy and cross‐sectional analysis showed clear differences in the appearance of the films with copper deposited onto the polypyrrole surface and copper inserted into the polypyrrole matrix.