Investigating CO2 storage properties of C2N monolayer functionalized with small metal clusters

Abstract

<p>By using first principles calculations based on density functional theory (DFT), we studied a mechanism for the efficient capture of multiple CO₂ molecules on TM_n doped C₂N monolayer (TM_n = Ti_n and Sc_n with <i>n</i> = 1–3). A comprehensive analysis revealed that all the metal clusters bind strongly to C₂N monolayer; however the bindings of Sc_n are stronger than those of Ti_n clusters. On the basis of electronic structure calculations, it was found that uniformly distributed metal clusters transformed the semiconducting C₂N monolayers into metal. The magnetic states of C₂N also changed from non-magnetic to magnetic upon the introduction of metal dopants. We found that a maximum of six CO₂ molecules could be adsorbed on C₂N doped with dimers and trimers of both Sc and Ti clusters. Our van der Waals corrected DFT calculations showed that the average binding energies per CO₂ molecule decreased with the increase in the number of incident CO₂ molecules to metal functionalized C₂N. Overall, Sc_n doped C₂N monolayer anchored the CO₂ molecules stronger than that of Ti_n doping. We believe that these findings would pave the way for the synthesis of efficient CO₂ capture medium.</p>