Density functional theorystudy ofCO2capture and storage promotion using manipulation of graphyne by 3dand 4dtransition metals

In this work, the electronic and structural properties of 3dand 4dtransition metal (TM)-decorated graphyne (GY) (TM-GY) toward CO(2)adsorption were studied using the D3-corrected density functional theory (DFT-D3) method. Then, CO(2)capture and storage (CCS) of the most stable structures were investigated. Results show that the most stable site for all TM decoration is the center of the 12-membered ring with various distances from carbon plane, and GY decorated with Ni and Zn from 3dand Zr and Cd from 4dTMs are also the most and the least stable, energetically with E(b)of -5.834, -0.467, -6.181, and -0.963 eV, respectively. Evaluation of the adsorption behavior of CO(2)on TM-GY reveals that the strongest adsorption energies belong to Cr and Mo-GY (-1.502 and -1.117 eV, respectively), and for all 3dand 4dTMs, the horizontal direction of CO(2)is more stable, energetically. Increasing CO(2)molecules, step by step, on Cr and Mo-GY shows that they can hold 13 and 18 CO(2)molecules with average E(ads)of -0.374 and -0.330 eV/CO(2)and corresponding CO(2)storage capacities of 47.66 and 54.10 wt%, respectively. These findings show that Cr and Mo-GY can be used in the future as suitable candidates for CCS applications.