Electropolymerization: Further Insight into the Formation of Conducting Polyindole Thin Films

Abstract

Electropolymerization is a promising route to design new functional surfaces. In this work, we investigate electropolymerization of indole at polycrystalline Pt electrode surfaces in acidic sulfuric media using in situ nanogravimetry, electrochemical impedance spectroscopy, and direct current (dc) measurements applied simultaneously to elucidate the physical model of the electrified interface during this process. Monitoring the electrode mass change with a quartz crystal nanobalance allows quantification of the overall electropolymerization kinetics and, together with the dc-response, provides further insight into the dynamics of the film formation. Complementary electrochemical impedance spectroscopy measurements quantify specific parameters characterizing the processes which involve the interfacial charge transfer during the film growth. Importantly for various applications, it has been also demonstrated that the growth of polyindole thin films can be controlled using just molecular oxygen dissolved in the electrolytes.

Critical analysis of polyindole and its composites in supercapacitor application

“…Electrochemical polymerization methods are chiefly employed used in union with three-electrode assembly techniques like potentiostatic, galvanostatic, or potentiodynamic ( Fig. 2b) [17,26]. The advantages of these advance synthetic techniques involve excellent reduction-oxidation activity, and thermal and physical stability of the polymer synthetized and sluggish rate of degradation [17,25].…”

“…A systematic representation of electrochemical synthesis; b CVs acquired during the electrochemical synthesis of PIN[26] …”

Synthesis; Redox behaviour; Composites; Sensors; Biosensors; Supercapacitors; Electrocatalysis

“…Two examples will be presented below. The considerable difference between the anodic and cathodic peak potentials of the cyclic voltammograms for the poly(tetracyanoquinodimethane) (TCNQ) redox electrode has been explained by the formation of dimeric species; i.e., the slow formation of mixed-valence dimers during reduction (charging) and the fast re-oxidation of dimer dianions resulting in mixed-valence dimers during the discharging process [31]. The concentrations of the anion radicals and the dimer dianions were derived from UV-VIS spectroelectrochemical data.…”

Electropolymerization of thienyl tethered comonomers and application towards the electrocatalytic reduction of nitrobenzene

“…4 Chemical method is quite oen used to prepare polymer on large scale, but to study the electronic conductivity and/or electrochromic behaviour, deposition of polymer into a conducting matrix becomes necessary. 5 In this regard, electrochemical polymerisation technique offer advantages such as synthesis under mild conditions, deposition of polymer directly onto the conducting substrate (electrode) and consequent electrochemical characterization of the deposited polymer. 6 Electrochemical polymerization is frequently used for the synthesis of conducting polymers which show electrochromic behaviour.…”