Impact of Lignin Substitution on the Formation and Physicochemical Properties of Resorcinol-Furfural-Based Carbon Aerogels in Deep Eutectic Solvent.

Aligned with green chemistry principles and the pursuit of sustainable synthesis, we developed a lignin-resorcinol-furfural (LRF) gel system within a deep eutectic solvent (DES), in which lignin partially replaces resorcinol and furfural serves as a bio-based alternative to formaldehyde. We further examined the correlation between the lignin substitution ratio (65-90%) and the gelation kinetics, microstructure, and electrochemical performance of the resulting carbon aerogels (LRFC). The findings reveal that the lignin substitution ratio exerts a critical influence on both the crosslinking uniformity and the overall network architecture of the resulting LRFC. The results demonstrated that LRFC65, with a lignin substitution ratio of 65%, exhibited the optimal electrochemical performance: a specific capacitance of 117.2 F g-1 at a current density of 0.2 A g-1, along with lower charge transfer and diffusion resistance. This work offers promising prospects for high-value bio-based furfural and lignin valorization.