(167d) Nanostructured Carbon from Chemically Modified Bacterial Nanocellulose: A Green Route to Supercapacitor Electrodes

The global movement toward a carbon-neutral society necessitates a departure from fossil-based activated carbon materials and promotes the adoption of sustainable biomass precursors, such as cellulose. Bacterial nanocellulose(BNC), with its high crystallinity, purity, and mechanical robustness, is a promising candidate for producing nanostructured carbon materials. However, low yield and high production costs hinder its practical application. In our previous study, we addressed this limitation by cultivating Komagataeibacter sucrofermentans using crude glycerol, a biodiesel industry byproduct, achieving cost-effective BNC production.

In this study, we employed both ex-situ and in-situ nitrogen doping, along with ex-situ KOH activation, to enhance the electrochemical properties of BNC-derived carbon. Nanostructured porous carbon materials were synthesized via a one-step carbonization of BNCs that were chemically modified through ex-situ and in-situ nitrogen doping and ex-situ KOH treatment. The roles of KOH activation and nitrogen incorporation were investigated in relation to pore structure development and capacitive performance. The resulting nitrogen-doped carbons exhibited specific capacitances ranging from 140 F g^-1 to nearly 500 F g^-1, indicating the synergistic effects of KOH and nitrogen. KOH functioned as a pore-forming agent, while nitrogen served as electrochemically active sites.

These results highlight the synergistic effects of nitrogen and KOH doping in enhancing the capacitive performance of BNC-derived carbon. This work further demonstrates the feasibility of converting biodiesel-derived industrial waste into high-value carbon materials for supercapacitor electrodes, contributing to both environmental sustainability and economic viability while supporting the advancement of circular bioeconomy and green energy technologies.