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

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.