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

Abstract

Nitrogen-doped porous carbon nanotubes@MnO₂ (N-CNTs@MnO₂ ) nanocomposites are prepared through the in situ growth of MnO₂ nanosheets on N-CNTs derived from polypyrrole nanotubes (PNTs). Benefiting from the synergistic effects between N-CNTs (high conductivity and N doping level) and MnO₂ nanosheets (high theoretical capacity), the as-prepared N-CNTs@MnO₂ -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 MnO₂ nanosheets (128 F g^-1 ) and PNTs (42 F g^-1 ) in 0.5 m Na₂ SO₄ solution. Meanwhile, the capacitance retention of 86.8 % (after 1000 cycles at 10 A g^-1 ) indicates an excellent electrochemical performance of N-CNTs@MnO₂ prepared in this work.