DFT-Based Study for the Enhancement of CO2 Adsorption on Metal-Doped Nitrogen-Enriched Polytriazines.

Abstract

Nitrogen-enriched polytriazine (NPT), a carbon nitride-based material, has received much attention for CO2 storage applications. However, to enhance the CO2 uptake capacity more efficiently, it is necessary to understand the interaction mechanism between CO2 molecules and NPT through appropriate modification of the structures. Here, we introduce a method to enhance the CO2 adsorption capacity of NPT by incorporating metal atoms such as Sn, Co, and Ni into the polytriazine network. DFT calculations were used to investigate the CO2 adsorption mechanism of the polytriazine frameworks by tracking the interactions between CO2 and the various interaction sites of NPT. By optimizing the geometry of the pure and metal-containing NPT frameworks, we calculated the binding energy of metal atoms in the NPT framework, the adsorption energy of CO2 molecules, and the charge transfer between CO2 molecules and the corresponding adsorption systems. In this work, we demonstrate that the CO2 adsorption capacity of NPT can be greatly enhanced by doping transition-metal atoms into the cavities of NPT.