Theoretical Investigation of Carbon Dioxide Adsorption on Li(+)-Decorated Nanoflakes

Recently, the capture of carbon dioxide, the primary greenhouse gas, has attracted particular interest from researchers worldwide. In the present work, several theoretical methods have been used to study adsorption of CO(2) molecules on Li(+)-decorated coronene (Li(+)@coronene). It has been established that Li(+) can be strongly anchored on coronene, and then a physical adsorption of CO(2) will occur in the vicinity of this cation. Moreover, such a decoration has substantially improved interaction energy (E(int)) between CO(2) molecules and the adsorbent. One to twelve CO(2) molecules per one Li(+) have been considered, and their E(int) values are in the range from −5.55 to −16.87 kcal/mol. Symmetry-adapted perturbation theory (SAPT0) calculations have shown that, depending on the quantity of adsorbed CO(2) molecules, different energy components act as the main reason for attraction. AIMD simulations allow estimating gravimetric densities (GD, wt.%) at various temperatures, and the maximal GDs have been calculated to be 9.3, 6.0, and 4.9% at T = 77, 300, and 400 K, respectively. Besides this, AIMD calculations validate stability of Li(+)@coronene complexes during simulation time at the maximum CO(2) loading. Bader’s atoms-in-molecules (QTAIM) and independent gradient model (IGM) techniques have been implemented to unveil the features of interactions between CO(2) and Li(+)@coronene. These methods have proved that there exists a non-covalent bonding between the cation center and CO(2). We suppose that findings, derived in this theoretical work, may also benefit the design of novel nanosystems for gas storage and delivery.