Boron-doped helical carbon nanotubes as active supercapacitor cathode materials: preparation and electrochemical properties

Boron-doped helical carbon nanotubes (B-HCNTs) were synthesized by annealing HCNTs under the boric acid presence. Successful B incorporation into the HCNT matrix was confirmed by the extensive characterization performed by field emission scanning, transmission electron microscopies, X-ray diffraction, Raman spectroscopy, as well as X-ray photoelectron spectroscopy. B doping did not damage the HCNT structures. However, B presence and content affected B-HCNT electrochemical performance, which was tested by cyclic voltammetry, galvanostatically, and by electrochemical impedance spectroscopy. The B-HCNTs demonstrated excellent energy storage performance, cycling stability, and specific capacitance equal to 212.6 F g−1 at 1 A g−1. Thus, HCTN capacity was increased significantly after B doping.