Functionalization of textile cotton fabric with reduced graphene oxide/MnO2/polyaniline based electrode for supercapacitor

Abstract

In this work, a new cotton electrode has been synthesized by coating ternary materials of reduced graphene oxide (rGO), manganese dioxide (MnO2), and polyaniline (PANi) on textile cotton fabric. First, Graphene oxide was deposited on cotton fibers by a simple 'dip and dry' method and chemically reduced into rGO/cotton fabric. MnO2 nanoparticles were accumulated on rGO/cotton fabric by in situ chemical deposition method. PANi layer was coated on rGO/MnO2/cotton fabric by in situ oxidative polymerization technique. A thin PANi coating layer acts as a protective layer on rGO/MnO2/cotton fabric to restrain MnO2 nanoparticles and rGO from dissolution in H2SO4 acidic electrolyte. The specific surface area of cotton electrode was measured using the Brenauer-Emmett-Teller (BET) method. The cyclic voltammetry (CV) results show that the cotton electrode has good capacitive behavior. The ternary cotton electrode exhibits high specific capacitance values of 888 F g-1 and 252 F g-1 at a discharge current density of 1 A g-1 and 25 A g-1 in 1 M H2SO4 electrolyte solution. The high areal specific capacitance of 444 Fcm-2 was achieved for as-fabricated electrode. Also, the cotton electrode retains around 70% of specific capacitance after 3000 cycles at charge-discharge current density of 15 A g-1. The slow decrease in specific capacitance is observed with increased discharge current density which proves its excellent rate capability. These results of rGO/MnO2/PANi/cotton fabric electrode show that this can be an excellent electrode for supercapacitor in energy storage devices.