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 (MnO 2 ), 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. MnO 2 nanoparticles were accumulated on rGO/cotton fabric by in situ chemical deposition method. PANi layer was coated on rGO/MnO 2 /cotton fabric by in situ oxidative polymerization technique. A thin PANi coating layer acts as a protective layer on rGO/MnO 2 /cotton fabric to restrain MnO 2 nanoparticles and rGO from dissolution in H 2 SO 4 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 H 2 SO 4 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/MnO 2 /PANi/cotton fabric electrode show that this can be an excellent electrode for supercapacitor in energy storage devices.