Renewable biomass bougainvillea petals-derived porous carbon through KOH activation and B/N co-doping: Synergistic contribution and charge storage mechanism

Heteroatom doping and chemical/physical activation can be considered as two effective pathways to enhance the electrochemical performance of biomass-based porous carbon electrodes through distinct operating mechanisms. Herein, a series of biomass bougainvillea petal-derived carbon materials are successively synthesized by different strategies, among which BP-4 carbon material with hierarchical porous architecture is successfully fabricated through a composite strategy combining KOH activation and B/N co-doping. After a series of characterization tests of these synthesized materials, it is found that the BP-4 porous carbon possesses an appropriate graphitization degree, a large specific surface area, a suitable pore structure and high B and N contents. Due to the synergistic contribution of boosting the specific surface area by the KOH pore-forming activation process and generating additional faradic pseudocapacitance by introducing B/N functional groups, the BP-4 electrode exhibits brilliant electrochemical properties in terms of specific capacitance, rate capability, electrical conductivity and cycle life compared to other three carbon electrodes. Furthermore, the CV kinetic analysis of four carbon electrodes is systematically explored, which expounds the immense variability of charge storage mechanisms. This study offers insights for the exquisite design of biomass-based porous carbon material electrode with abundant electroactive sites and broadened electrochemical potential for the practical application of renewable natural biomass materials in energy storage.