Doping-induced enhancement of CO2 adsorption on negatively charged C3N nanosheet: Insights from DFT calculations

Abstract

It is an increasing need to explore advanced materials and technologies for CO2 capture to weaken its impact on the environment. For the first time, it is demonstrated that a suitable doping can dramatically increase CO2 adsorption capacity of negatively charged C3N nanosheets using density functional theory calculations. For example, the CO2 adsorption energy on 2e− negatively charged P doped C3N (P-C3N) nanosheet can reach −2.233 eV, which is about 600% larger than that on 2e− negatively charged C3N nanosheet. Additionally, the negatively charged P-C3N nanostructure exhibits good CO2/CH4, CO2/H2 and CO2/N2 selectivity. Therefore, P-C3N nanosheet may be a very promising negatively charge-regulated CO2 sorbent. More importantly, charge modulation strategies offer the potential for spontaneous, controllable CO2 storage and release. Furthermore, it is manifested that the increased interactions between CO2 and negatively charged P-C3N monolayer are attributed to the heterogeneous charge density distribution of P-C3N monolayer and the hybridization of p orbits of C and P atoms. These theoretical predictions could shed new light on designing feasible high-performance CO2 sorbents.