Nanochannel Highways in Hybrid Lamellar Membranes: Computational Simulation of Electric Field-Guided CO2 Transport via Molecular Sieving for Ultra-efficient Separation

QK Yin and MH Wang and CF Xia and BJ Wei and ZJ Wang and SY Liu and W Lyu and B Liao and Z Sun and XQ Lu, ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 13, 12509-12522 (2025).

DOI: 10.1021/acssuschemeng.5c03811

The excessive weakness and strength of the interactions between graphene and g-C3N4 with CO2 pose challenges for CO2 separation. Here, we proposed a gas separation nanochannel composed of the interlayer spacing in a two-dimensional graphene/g-C3N4 (Gra/CN) membrane to solve the issue by molecular dynamics simulation. Graphene is a finely tuned electrostatic interaction membrane in direct contact with CO2 within the nanochannel. Due to the proper interaction between Gra/CN and CO2, Gra/CN maintains high CO2 permeance and selectivity under mixed gas conditions at different interlayer spacings, which confirms the good applicability for CO2 separation. The nanochannel becomes a highway for CO2 separation under an external electric field (E-field) of 1.0 x 10(-4) V& Aring;(-1) along the z-axis; the CO2 permeance reaches 1.17 x 10(-3) mols(-1)m(-2)Pa-1 through computational simulation, marking a substantial enhancement of approximately 60.3% relative to conditions without E-field. Simultaneously, the solubility coefficient rises to 4.48 x 10(7) molm(-4)Pa as E-field in the z-axis. Moreover, the calculated energy consumption of the CO2 separation is 0.017 GJton(-1), which is below the theoretical minimum value of 0.050 GJton(-1), demonstrating practical feasibility and efficiency in real-world applications. The results of this work highlight the significant role of the synergistic effect of the hybrid membrane gas separation nanochannel and E-field in enhancing CO2 solubility and permeance, providing valuable theoretical guidance for CO2 separation.

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