Electrochemical assembly of homogenized poly(3,4-ethylenedioxythiophene methanol)/SWCNT nano-networks and their high performances for supercapacitor electrodes

Homogenized PEDOT/CNT composite is difficult to be fabricated directly from aqueous solution without any solubilizers due to the limitation of insoluble EDOT. Through the introduction of hydroxymethyl group (MeOH) on the EDOT side chain, the designed EDOT-MeOH has very good solubility in aqueous solution. Herein, we firstly used one-step electrochemical co-deposition method to prepare a homogenized PEDOT-MeOH/SWCNT nano-network from the mixed aqueous solution of EDOT-MeOH and SWCNT. SEM and TEM indicated that PEDOT-MeOH uniformly coated on the surface of SWCNT and formed a three-dimensional interpenetrating network. With the increase in the deposited cycles, the thickness of PEDOT-MeOH coating on SWCNT increased regularly. The optimized PEDOT-MeOH/SWCNT nano-network in H2SO4 solution had a specific capacitance of 114.3 mF cm−2 at 5 mV s−1, which was higher than that of PEDOT-MeOH (58.8 mF cm−2), and showed good cycle stability of 80% after 5000 cycles. The enhanced performance mainly comes from the three-dimensional interpenetrating nano-network and the synergistic effect between SWCNT and PEDOT-MeOH. This work realized the facile combination of PEDOT derivatives and SWCNT from pure water solution, which will have good application in electrochemical energy storage devices and in the biosensors and bioelectronics areas due to its good biocompatibility.