Nanoarchitectonics of carbon-based electrodes via activated carbon/carbon composite xerogels by CO2

Abstract

Carbon/carbon (C/C) composites, characterized by trimodal porous structures and highly tunable surfaces, offer promising prospects for electrochemical applications within the framework of nanoarchitectonics. However, recent research lacks systematic investigations into property-controlled performance. This study explores the effects of functional groups, surface area, and pore architecture in CO2-activated C/C composite xerogels synthesized from resorcinol-formaldehyde (RF) sol and cotton fibers (CFs). Increased activation time and CF content enhanced porosity, functional group density (O[sbnd]H and C[dbnd]O), and structural disorder. The macropores introduced by CFs facilitated deeper CO2 penetration, thereby increasing meso‑ and microporosity, surface area, and specific capacitance. Electrochemical performance measured through cyclic voltammetry and charge/discharge analysis revealed that capacitance was governed primarily by surface area rather than pore geometry. Specific capacitance and surface area increased from 144 to 344 F g⁻¹ and from 575 to 1471 m² g⁻¹, respectively, under 0.5 A g⁻¹ discharge.