Charge controlled switchable CO2/N2 separation for g-C10N9 membrane: Insights from molecular dynamics simulations. (July 2018)

• Record Type: Journal Article
• Authors: Chang, Xiao; Zhu, Lei; Xue, Qingzhong; Li, Xiao; Guo, Tianchao; Li, Xiaofang; Ma, Ming
• Is Part Of: Journal of CO₂ utilization. Volume 26(2018)
• Page Start: 294
• Page End: 301
• Publication Date: 2018-07
• Subjects: Charge control -- g-C10N9 membrane -- CO2/N2 separation -- Selectivity -- Molecular dynamics simulations; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2018.05.017
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Using molecular dynamics simulations, we demonstrate that charge control is an excellent method for g-C10 N9 membrane to realize switchable CO2 /N2 separation. Highlights: A new g-C10 N9 membrane is used for CO2 /N2 separation. Injecting positive charge into g-C10 N9 can greatly enhance its N2 /CO2 selectivity. We elucidate the CO2 /N2 separation mechanism of charge controlled g-C10 N9 membrane. Abstract: Using molecular dynamics simulations, we theoretically demonstrate that the CO2 /N2 separation performance of g-C10 N9 membrane can be controlled by introducing different charges into this membrane. It is found that neutrally charged g-C10 N9 membrane is non-selective for CO2 /N2 separation resulting from its large pore size. However, positively charged g-C10 N9 membrane with charge density of 88 × 10 13 e/cm 2 exhibits 100% N2 /CO2 selectivity, and the CO2 /N2 selectivity of negatively charged g-C10 N9 membrane with charge density of -60 × 10 13 e/cm 2 is more than four times higher than that of neutrally charged g-C10 N9 membrane. Furthermore, it is shown that the CO2 /N2 separation performance of charged g-C10 N9 membrane is influenced by the number of CO2 molecules blocking at the pores and the binding energy between CO2 molecules and charged g-C10 N9 membrane, which are determined by positive or negative membrane charge and charge density. Our results manifest that charge control is an excellent method for g-C10 N9 membrane to realize switchable CO2 /N2 separation.