Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material

Abstract

We report spectroelectrochemical studies to investigate the charge storage mechanism of composite polypyrrole/lignin electrodes. Renewable bioorganic electrode materials were produced by electropolymerization of pyrrole in the presence of a water-soluble lignin derivative acting as dopant. The resulting composite exhibited enhanced charge storage abilities due to a lignin-based faradaic processes, which was expressed after repeated electrochemical redox of the material. The in-situ FTIR spectroelectrochemistry results show the formation of quinone groups, and the reversible oxidation-reduction of these groups during charge-discharge experiments in the electrode materials. The most significant IR bands include carbonyl absorption near 1705 cm -1 , which is attributed to the creation of quinone moieties during oxidation, and absorption at 1045 cm -1 which is due to hydroquinone moieties.after the discovery of metallic polyacetylene by Shirakawa, McDiarmid, Heeger, et al. 10 A strong interest in the development of new storage devices emerged at this time. The benefits of conductive polymers are their high electrical conductivity, processability, low cost and electrochemical reversibility. This is due to the presence of fast charge transfer in the polymeric chain, associated with intercalation/deintercalation of counter-ions during the redox process. 11,12 For many of these reasons, polypyrrole (PPy) seems to be a good candidate for this purpose, as one of the more stable materials, with relatively high theoretical specific capacity 75 mAh g -1 (with dopant) and a specific energy density ranging from 80 to 390 Wh kg −1 . 13,14 However, PPy doped by small, mobile counteranions such as perchlorates, still suffer from self-discharge, from insufficient charge storage density compared to inorganic materials used in secondary batteries, † These authors contributed equally to this work.

A New Synergetic Nanocomposite for Dye Degradation in Dark and Light

“…The peaks at 1040 cm −1 , 1331 cm −1 and 1420 cm −1 in both products correspond to O 2 2− species and 410 cm −1 corresponds to Zn-O bond38. The peaks at 3430, 2862, 1566, 1236, 965 cm −1 correspond to N-H, C-H, C=C, C-C-C and C-H sterching cofinfirming the presence of polypyrrole39. Figure 1c,d confirm single phasic cubic nanocrystalline ZnO 2 product (JCPDS card No.…”

Scalable lignin/graphite electrodes formed by mechanochemistry

“…The polypyrrole/LS hybrid materials show a discharge capacity of 72 mA h g À1 and the capacity decreases dramatically aer 100 charge-discharge cycles. 7 The PEDOT/LS hybrid materials display a discharge capacity of 34 mA h g À1 and retain 83% of the capacity aer 1000 charge-discharge cycles. 6 The PEDOT/ LS/PAAQ hybrid materials present a discharge capacity of 80 mA h g À1 and a retention capacity of 80% aer 10 000 charge-discharge cycles.…”

Scalable Asymmetric Supercapacitors Based on Hybrid Organic/Biopolymer Electrodes

“…The utility of the quinone/hydroquinone redox reaction to store charge has shown great potential in lignin/conjugated polymer polymeric complex system. [29][30][31][32] In these systems, lignin provides the quinone groups while the conducting polymer provides electrochemical accessibility to these functional groups. To further maximize the charge storage through quinone pseudocapacitance, we combined a conjugated polymer, PAAQ with integrated quinone, [33,34] with the PEDOT/lignin, resulting in a trihybrid electrode structure based on PEDOT/lignin complex and PAAQ (Figure 1a).…”