Oligoether Ester-Functionalized ProDOT Copolymers on Si/Monolayer Graphene as Capacitive Thin Film Electrodes

Abstract

In this study, electrochemical polymerization of 3,4-propylenedioxythiophene (ProDOT 1), ProDOT bearing oligoether ester (ProDOT-EO-ester 2) and their copolymerization onto homogeneously CVD coated nano-graphene/Si support is realized to attain graphene/ProDOT based copolymer hybrid nanostructures. By introducing oligoether side chain to ProDOT backbone and using different [ProDOT]/[ProDOT-EO-ester] molar ratios ensures a considerable decrease in oxidation potential of polymer allowing tunable properties to copolymers revealing improvement electrochemical capacitance and electrochemical activity which are clearly reflected by the experimental results. Capacitive behavior of copolymers is determined by electrochemical impedance spectroscopy, cyclic voltammetry. Moreover, The structural, morphological and spectroscopic characterization of the copolymers is investigated by XRD, AFM, SEM, EDX, FTIR, and Raman, respectively. By the increase of ProDOT in the copolymer composition, the higher dopant concentration is attained suggesting an enhanced conductivity agree well with the impedance and CV results, where the copolymerization of ProDOT 1 and ProDOT-EO-ester 2 in equal molarity results in the highest specific capacitance and redox activity. The adopted equivalent circuit model for polymers is in good agreement with the experimental data of impedance. Due to the difference in conjugated structure between ProDOT and ProDOT-EO-ester by the presence of the EO-ester group leads to a decrease in charge transfer resistance with increasing mole fraction of ProDOT-EO-ester. The charge transfer resistance of [ProDOT]0/[ProDOT-EO-ester]0 = 1:1 coated Si/graphene is nearly 51 and 24 times lower value compared to those of PProDOT and P(ProDOT-EO-ester) homopolymers coated Si/graphene, respectively, confirming that the copolymerization improves the electron conduction. By Mott-Schottky measurements, increasing mole fraction of ProDOT-EO-ester 2 in copolymer composition results in the alteration of semiconducting behavior. The developed graphene-polymer hybrid electrodes can be a potential candidate for energy storage devices.

Calotropis Gigantea Fiber─A Biogenic Reinforcement Material for Europium Substituted Hydroxyapatite/Poly(3,4-propylenedioxythiophene) Matrix: A Novel Ternary Composite for Biomedical Applications

“…The strong diffraction peaks at 2θ values of 31.43, 33.98, 35.24, 37.94, and 41.16°are attributed to Eu-HAP and no other secondary peaks were found, whereas the remaining peaks at 23.07 and 27.53°were assigned to PProDOT. 58 The major diffraction peaks identified for the Eu-HAP are in good agreement with the standard data for HAP (ICDD card No. 09-0432), whereas for the Eu-HAP (Figure 2b), the diffraction peak positions shifted toward the lower angles from the standard XRD patterns for HAP, indicating the substitution of Eu into the pure HAP sample.…”

Highly Stable Ag–Au Core–Shell Nanowire Network for ITO‐Free Flexible Organic Electrochromic Device

“…[ 48 ] The bands appearing at ≈815 and ≈865 cm −1 are associated with the vibrations of CSC bond in thiophene ring, while those at ≈1031 and ≈1092 cm −1 are the characteristic bending vibration of the COC in ProDOT. [ 49 ] The results suggest the uniform chemical composition throughout the polymer film. This finding was also in line with the DSC results, i.e., the polymer film was amorphous, because otherwise the vibration modes will vary depending on the specific crystallization status at various positions.…”

Polyaniline-Lignin Interpenetrating Network for Supercapacitive Energy Storage

“…One limitation of conducting polymers, however, is their relatively low charge capacity. A variety of approaches have been considered to boost the charge capacity of conducting polymers, such as incorporating redox-active side groups, organic/inorganic species, and redox active dopants, or synthesizing nanostructured polymers to increase the effective surface area for efficient electrode–electrolyte contact. − Furthermore, morphological and structural characteristics and electrochemical behavior of conducting polymers is strongly dependent on the type of counterions compensating the positive charge of the conjugated polymer chains during synthesis. Small anionic dopants such as chloride, perchlorate, p-toluenesulfoante, and dodecylbenzenesulfonate are susceptible to migration out of the electrodes over time, whereas the use of large (bio)­polymers as dopants leads to more stable confinement of the redox moieties within the conductive polymer matrix …”