Nowadays, materials for soft electronics are in high demand; among the different forms of conducting materials, conducting gels have become promising candidates. They provide both the electrical conductivity and mechanical flexibility, which are prerequisites for such applications. Herein, one-step facile preparation of polypyrrole–nanofibrillated cellulose (PPy–NFC) cryogels and their conversion to aerogels are reported. PPy–NFC was prepared via an in situ oxidative polymerization of pyrrole with iron(III) chloride in the presence of NFC under frozen conditions. The mechanical properties of the cryogels were improved by increasing the NFC content from 0.1 to 2 wt%. The tensile modulii of 432 kPa and 1055 kPa were achieved for cryogels and aerogels with 2 wt% of NFC, respectively. SEM micrographs of the aerogels show the formation of entangled three-dimensional porous networks with various pore sizes depending on the NFC content. Lightweight, flexible and conducting aerogels with high specific surface area (34.5–67.3 m² g⁻¹) were obtained. The conductivity of 31 S cm⁻¹ was attained when 0.7 wt% of NFC was used for cryogel preparation, which is significantly higher than conventional globular PPy. Additionally, aerogels showed improved ability to adsorb heavy metal ions (hexavalent chromium ions) from aqueous solutions owing to their high specific surface area and ion exchange properties.

In this paper, silver nitrate was used as an oxidant to prepare polyaniline, polypyrrole, and poly(3,4-ethylene dioxythiophene)/silver composites through a simultaneous oxidation/reduction process. In addition, p-phenylenediamine was added with 1 mole% relative to the concentrations of the monomers to accelerate the polymerization reaction. The prepared conducting polymer/silver composites were characterized by scanning and transmission electron microscopies to study their morphologies; Fourier-transform infrared and Raman spectroscopies to confirm their molecular structures; and thermogravimetric analysis (TGA) to study their thermal stabilities. The silver content in the composites was estimated by energy-dispersive X-ray spectroscopy, ash analysis, and TGA. The conducting polymer/silver composites were utilized for the remediation of water pollutants through catalytic reduction. Hexavalent chromium ions (Cr(VI)) were photocatalytically reduced to trivalent chromium ions, and p-nitrophenol was catalytically reduced to p-aminophenol. The catalytic reduction reactions were found to follow the first-order kinetic model. Among the prepared composites, polyaniline/silver composite has shown the highest activity for the photocatalytic reduction of Cr(VI) ions with an apparent rate constant of 0.226 min^–1 and efficiency of 100% within 20 min. Additionally, poly(3,4-ethylene dioxythiophene)/silver composite showed the highest catalytic activity towards the reduction of p-nitrophenol with an apparent rate constant of 0.445 min^–1 and efficiency of 99.8% within 12 min.