Promoting hierarchical porous carbon derived from Bamboo via copper doping for high-performance supercapacitors

Porous carbon obtained from biomass has emerged as a significant source of electrode materials for supercapacitors. However, the microporous structure of biomass itself and the low doping of elements limit its electrochemical performance. In this work, a Cu doped bamboo/polypyrrole (PPy) based derived porous carbon material was prepared by polymerization of one-dimensional linear polypyrrole in bamboo residual cell walls and synergistic catalysis of citric acid (CA) and copper sulfate (CuSO4) during hydrothermal carbonization. Thanks to the introduction of PPy and the synergistic catalytic effect of CA and CuSO4, the prepared carbon materials had a more moderate pore structure, good heteroatom doping degree, and a richer variety of photo energy groups. The optimized carbon material (HBC/N-CA-Cu) had a large specific surface area (1987.76 m2 g−1) and good capacitive performance (508.50 F g−1 at 0.5 A g−1). The assembled symmetric supercapacitors delivered an energy density of 17.42 Wh kg−1 at the power density of 5000 W kg−1 in Na2SO4 solution. After cycling for 12,000 at a current density of 5 A g−1, the initial specific capacitance could still be maintained at 94.1 %, demonstrating good practical application potential.