MOF-derived N-doped carbon bubbles on carbon tube arrays for flexible high-rate supercapacitors

N-doped carbon bubbles homogenously dispersed on highly conductive carbon tube arrays scaffold are derived from ZnO@ZIF-8 nanoarrays template through in situ catalytic decomposition of ethanol and reduction-evaporation process. The as-obtained hierarchical carbon tube connected N-doped carbon bubbles arrays possess well interconnected micro-/mesopores and large specific surface area, which are expected to improve both the specific capacitance and rate capability of carbon-based electrochemical capacitors. The hierarchical porous N-doped carbon nanostructures yield a remarkable rate capability with 56.8% capacitance retention when the current density ranges from 1 to 200 mA cm−2, and an excellent long-term cycle stability with 98.5% capacitance retention after 10,000 continuous cycles in 1 M H2SO4 aqueous solution under three-electrode mode. The symmetric supercapacitor delivers an areal capacitance of 580 mF cm−2 at 1 mA cm−2. Furthermore, the assembled symmetric device validates excellent mechanical stability and flexibility.