A poly(3,4-ethylenedioxypyrrole)-Au@WO3 -based electrochromic pseudocapacitor.

A poly(3,4-ethylenedioxypyrrole)-gold nanoparticle (Au)-tungsten oxide (PEDOP-Au@WO3 ) electrochromic supercapacitor electrode capable of optically modulating solar energy while simultaneously storing/releasing energy (in the form of charge) was fabricated for the first time. WO3 fibers, 50 to 200 nm long and 20 to 60 nm wide, were synthesized by a hydrothermal route and were electrophoretically deposited on a conducting substrate. Au nanoparticles and PEDOP were coated over WO3 to yield the PEDOP-Au@WO3 hybrid electrode. The inclusion of Au in the hybrid was confirmed by X-ray diffraction, Raman spectroscopy, and energy-dispersive X-ray analyses. The nanoscale electronic conductivity, coloration efficiency, and transmission contrast of the hybrid were found to be significantly greater than those of pristine WO3 and PEDOP. The hybrid showed a high specific discharge capacitance of 130 F g(-1) during coloration, which was four and ten times greater than the capacitance achieved in WO3 or PEDOP, respectively. We also demonstrate the ability of the PEDOP-Au@WO3 hybrid, relative to pristine PEDOP, to perform as a superior counter electrode in a solar cell, which is attributed to a higher work function. The capacitance and redox switching capability of the hybrid decreases insignificantly with cycling, thus establishing the viability of this multifunction hybrid for next-generation sustainable devices such as electrochromic psuedocapacitors because it can concurrently conserve and store energy.

Highly conductive poly(3,4-ethylenedioxypyrrole) and poly(3,4-ethylenedioxythiophene) enwrapped Sb2S3 nanorods for flexible supercapacitors.

Composites of poly(3,4-ethylenedioxypyrrole) or PEDOP and poly(3,4-ethylenedioxythiophene) or PEDOT enwrapped Sb2S3 nanorods have been synthesized for the first time for use as supercapacitor electrodes. Hydrothermally synthesized Sb2S3 nanorods, several microns in length and 50-150 nm wide, offer high surface area and serve as a scaffold for coating conducting polymers, and are a viable alternative to carbon nanostructures. Fibrillar morphologies are achieved for the PEDOP-Sb2S3 and PEDOT-Sb2S3 films in contrast to the regular granular topologies attained for the neat polymers. The remarkably high nanoscale (∼5 S cm(-1)) conductivity of the Sb2S3 nanorods enables facile electron transport in the composites. We constructed asymmetric supercapacitors using the neat polymer or composite and graphite as electrodes. High specific capacitances of 1008 F g(-1) and 830 F g(-1) (at 1 A g(-1)), enhanced power densities (504 and 415 W kg(-1)) and excellent cycling stability (88 and 85% capacitance retention at the end of 1000 cycles) are delivered by the PEDOP-Sb2S3 and PEDOT-Sb2S3 cells relative to the neat polymer cells. A demonstration of a light emitting diode illumination using a light-weight, flexible, supercapacitor fabricated with PEDOP-Sb2S3 and carbon-fiber cloth shows the applicability of Sb2S3 enwrapped conducting polymers as sustainable electrodes for ultra-thin supercapacitors.