Sandwiched MoS2/polyaniline nanosheets array vertically aligned on reduced graphene oxide for high performance supercapacitors

Abstract MoS 2 /polyaniline/reduced graphene oxide hierarchical nanosheets (denoted as MoS 2 /PANI/rGO HNSs) with novel structure of sandwiched MoS 2 /PANI nanosheets array vertically align on rGO are successfully synthesized and investigated as supercapacitor electrode in aqueous electrolyte (1 M H 2 SO 4 ). In this hierarchical nanosheets, PANI chains are intercalated into MoS 2 interlayers constructing sandwiched MoS 2 /PANI nanosheets and restrict the volume change itself, meanwhile the sandwiched MoS 2 /PANI nanosheets array vertically align on rGO nanosheets creating intimate and sufficient hetero-interface between PANI, MoS 2 and rGO layers. Thus excellent conductivity and ultrahigh reactive surface area are achieved and leads to superior supercapacitance. In the three-electrode system, the MoS 2 /PANI/rGO-300 HNSs show a capacitance of 330.7 F g -1  at current density of 10 A g −1 at first cycle, and have capacitance retention about 81.9% after 40,000 cycles. Assembled as MoS 2 /PANI/rGO-300//MoS 2 /PANI/rGO-300 symmetric supercapacitor, it exhibits a capacitance of 97.8 F g -1  at current density of 2 A g −1 at first cycle. After 20,000 cycles, 84.2% of initial capacitance is retained. When assemble asymmetric supercapacitor using MoS 2 /PANI/rGO-300 HNSs as cathode and active carbon (AC) as anode, it still shows a high capacitance of 73.3 F g -1  at current density of 2 A g −1 at first cycle, retains 87.9% after 20,000 cycles.