Electrodeposition and cycling of polypyrrole

Abstract

Polypyrrole has been electrodeposited at a constant current density of 4 mA cm−2 onto Pt from 0.1 M pyrrole, 0.1 M NBu4 BF4 in dry CH3CN. The thickness of the polypyrrole has been varied over a wide range of 0.02 to 50 μm. Elemental analysis reveals an excess of hydrogen in the polymer. The electrochemical equivalent corresponds to an insertion of 25–35 mole % BF4‐anions and a current efficiency of 80–100% for the electrodeposition process. SEM technique shows a highly textured material at a thickness larger than 1 μm. Reversible water vapour adsorption of this material has been detected. The potential/time curve during galvanostatic electrodeposition is without special features. The start potential, USSCE = 0.9 V, is relatively negative. A slight decay of potential in the course of the electrodeposition of thick layers is explained in terms of increasing surface roughness. Cyclic voltammetry has been used for a systematic investigation into the role of the positive and negative endpotentials. The importance of a total primary discharge after electrodeposition has been clarified. At a film thickness d exceeding 1 μm, the cyclovoltammetric curve degenerates, and the anodic peak flattens and shifts to more positive potentials. Active mass utilization decreases with increasing d and with increasing voltage scan rate vs. The plot of anodic peak current density vs. vs is linear for layers below 1 μm thickness. For thick layers and at high vs, deviations occur, indicating a transport limitation in the film. As the film is not homogeneous, a quantitative evaluation is not possible.

Effect of Deposition Parameters on Electrochemical Properties of Polypyrrole-Graphene Oxide Films

“…The extent of the increase in deposition charge was higher than expected, which indicates the marked participation of residual oxygen groups in reduced GO for the nucleation of PPy. On the other hand, a current flattening occurs upon cycling, which indicates a transport limitation in the PPy film [39]. The increase in GO loading appears to only slightly increase the deposition charge of PPy, which can be attributed to the lower oxygen groups in the reduced GO.…”

Characterization of electrochemically synthesized alkylpyrrole intrinsically conducting polymers

“…The voltammetric behavior was found to be strongly cycling time-dependent and rather complex when compared with standard cyclic voltammetric data mentioned in the polypyrrole literature [12] and this degree of complexity makes a reliable assignment of oxidation and reduction waves difficult [7].…”

Graphite, Carbonaceous Materials and Organic Solids as Active Electrodes in Metal‐Free Batteries

“…One of the most important is the nominal thickness d, [20] of the active layer. (4), (6) and (7), respectively.…”