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Capacitive deionization (CDI) is a trending water desalination method during which the impurity ions in water can be removed by electrosorption. In this study, nano-manganese dioxide (MnO2) and reduced graphene oxide (rGO)-doped polyacrylonitrile (PAN) composite fibers are fabricated using an electrospinning technique. The incorporation of both MnO2 and rGO nanomaterials in the synthesized fibers was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The electrochemical characteristics of electrode materials were examined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and constant current charge–discharge cycles (CCCDs). The specific capacitance of the PAN electrode increased with increasing MnO2 and rGO contents as well as when thermally treated at 280 °C. Thermally treated composite fibers with 17% (w/w) MnO2 and 1% (w/w) rGO (C-rGOMnPAN) were observed to have the best electrochemical performance, with a specific capacitance of 244 F g−1 at a 10 mV s−1 scan rate. The electrode system was used to study the removal of sodium chloride (NaCl), cadmium (Cd2+) and lead (Pb2+) ions. Results indicated that NaCl showed the highest electrosorption (20 472 C g−1) compared to two heavy metal salts (14 260 C g−1 for Pb2+ and 6265 C g−1 for Cd2+), which is most likely to be due to the ease of mass transfer of lighter Na+ and Cl− ions; When compared, Pb2+ ions tend to show more electrosorption on these fibers than Cd2+ ions. Also, the C-rGOMnPAN electrode system is shown to work with 95% regeneration efficiency when 100 ppm NaCl is used as the electrolyte. Hence, it is clear that the novel binder-free, electrospun C-rGOMnPAN electrodes have the potential to be used in salt removal and also for the heavy metal removal applications of water purification.

There is an increasing interest on robust electrically conductive textiles with light weight and flexibility to meet the applications in wearable electronics. Current challenge is to fabricate such structures with feasible application strategies that can be readily scalable and provide higher mechanical stability of the conductive media on the textile matrix to withstand constant stretch and shear forces. We report a strategy to address these challenges, by using a “screen printing process” employing conductive carbon black ink. We produced conductive fabrics with liner resistance of less than 71 Ω cm−1. These textile materials showed stable conductivity up to 25% strain. Microscopic studies revealed that at strains lower than 25%, percolation pathways in the conductive media increases resulting lowering of the liner resistance. However, further stretching of over 25% resulted increase of resistance due to separation of conductive pathways. Ohmic heating application of the resulted fabrics showed fast response rate and no significant hysteresis. The conductive print was stable over long period of heating over number of cycles. These feasible conductive fabric fabrication pathways can provide new avenues in designing and manufacturing of wearable heat management and electronic applications.