Effective synthesis of nitrogen doped carbon nanotubes over transition metal loaded mesoporous catalysts for energy storage of supercapacitor applications

In the present work, the nitrogen doped carbon nanotubes (NCNTs) were prepared over various transition metal loaded mesoporous SBA-15 catalysts by the CVD method for supercapacitor application. Mesoporous Siliceous SBA-15 support and transition metals (Cr, Fe, Co, Ni and Cu) loaded SBA-15 (M/SBA-15) catalysts were prepared through hydrothermal and wet impregnation process, respectively. The catalytic performance of all the prepared catalysts were evaluated by synthesizing NCNTs by CVD at 800 °C using triethylamine as the precursor. The NCNTs produced over Ni/SBA-15 have an outstanding specific capacitance of 263 F g−1 at 0.5 A g−1 in 1.0 M H2SO4 aqueous solution according to the electrochemical investigations because of its increased nitrogen content of 3.2 at.%. Furthermore, a two-electrode based symmetric device was construct and tested. The fabricated device showed the specific capacitance of 113 F g−1 at 0.5 A g−1 with high energy density of 10 W h Kg−1 at the power density of 333 W kg−1. The NCNT showed 96 % of capacitance retention even after 1000 cycles. The synergism of high nitrogen content and bamboo-like graphitized structure resulted in excellent specific capacitance, better cycle life and rate performance of the prepared NCNTs as supercapacitor electrode.