In Situ Growth of MnO2 Nanosheets on N-Doped Carbon Nanotubes Derived from Polypyrrole Tubes for Supercapacitors

Graphical N-CNTs@MnO 2 nanocomposites have been successfully prepared by in situ growing MnO 2 nanosheets on N-doped carbon nanotubes (CNTs) derived from polypyrrole nanotubes. The as-prepared nanocomposites showed good capacitance and cycling stability as supercapacitor electrode materials. Nitrogen-doped porous carbon nanotubes@MnO 2 ( N -CNTs@MnO 2 ) nanocomposites are prepared through the in situ growth of MnO 2 nanosheets on N-CNTs derived from polypyrrole nanotubes (PNTs). Benefiting from the synergistic effects between N-CNTs (high conductivity and N doping level) and MnO 2 nanosheets (high theoretical capacity), the as-prepared N-CNTs@MnO 2 -800 nanocomposites show a specific capacitance of 219 F g −1 at a current density of 1.0 A g −1 , which is higher than that of pure MnO 2 nanosheets (128 F g −1 ) and PNTs (42 F g −1 ) in 0.5 m Na 2 SO 4 solution. Meanwhile, the capacitance retention of 86.8 % (after 1000 cycles at 10 A g −1 ) indicates an excellent electrochemical performance of N-CNTs@MnO 2 prepared in this work.