Simulation of CO₂ Adsorption on Pristine and Lithium-Decorated Few-Layers Graphene: Insights from Grand Canonical Monte Carlo Simulations

In this study, Grand Canonical Monte Carlo simulations were performed in order to investigate the adsorption behavior of CO2 on pristine and lithium-decorated few-layers graphene. We systematically explored the impact of key morphological parameters─namely, the number of graphene layers, interlayer pore width, and lithium surface coverage─on the adsorption capacity, under various pressure regimes. Our results demonstrate that lithium doping significantly enhances CO2 uptake, achieving up to a 20-fold increase at partial pressures below atmospheric. Furthermore, we developed a semiempirical model based on an exponential-modified Langmuir isotherm that accurately reproduces the simulation data and enables the inversion of experimental isotherms to extract the structural parameters. This methodology bridges the gap between molecular simulations and experimental characterization and underscores the importance of accurately tuning pore geometry and chemical functionality to optimize adsorption under realistic flue gas conditions.