Ca coated B40 fullerene: A promising material for CO2 storage and separation

Highlights: • Ca atoms are unlikely to form clusters on B₄₀. • Each Ca atom on B₄₀ has the capacity to store four CO₂ molecules. • The average adsorption energy of CO₂ in 24CO₂@B₄₀ is −0.54 eV. • Ca coated B₄₀ is capable of separating CO₂ from various gas mixtures. Density functional theory calculations were used to investigate the adsorption behavior of Ca coated B₄₀ fullerene toward CO₂ molecules. It was found that Ca atoms are unlikely to form clusters on B₄₀. CO₂ molecules can be effectively adsorbed on the Ca coated B₄₀, as evidenced by large negative adsorption energies and significant charge transfer effects. Each Ca atom on B₄₀ may adsorb four CO₂, with an average adsorption energy of −0.54 eV which falls within the range proposed for an ideal CO₂ adsorbent. Furthermore, Ca coated B₄₀ exhibits high selectivity for CO₂ from CO₂/N₂, CO₂/H₂, and CO₂/CH₄ gas mixtures.