Charge-controlled switchable CO2 capture and gas separation using BC3 nanosheets

Abstract

The technique of CO₂ capture and separation using charge-modulated sorbent materials holds promise for reducing CO₂ emissions. Density functional theory with long-range dispersion correction has been used to study the adsorption of CO₂, H₂, CH₄, and N₂ on BC₃ nanosheets with/without charge injections. We find that CO₂ is weakly adsorbed on pristine BC₃, but injection of 3 negative charges (3 e) can change the adsorption to chemical adsorption. Removing the charge results in the release of CO₂ without any energy barrier. A high capacity of 4.30 × 10¹⁴ cm⁻² can be achieved with 5 e charge injection, and CO₂ molecules could automatically desorb after charge removal. Additionally, negatively charged BC₃ exhibits high selectivity for separating CO₂ from other industrial gases such as CH₄, H₂, and N₂. Our findings provide useful guidance for the development of switchable CO₂ capture and storage materials.