High-efficiency helium separation through g-C2O membrane: A theoretical study

Abstract

It is significant to realize helium separation due to its wide application in welding process and cryogenic science. In this work, density functional theory (DFT) calculations and molecular dynamic (MD) simulations are performed to investigate the helium separation performance of g-C2O membrane. The DFT calculation results show that the energy barrier for He molecule passing through g-C2O membrane is only 0.04 eV while the energy barriers for Ne, Ar, CO2, CO, N2 and CH4 molecules are 0.13 eV, 0.89 eV, 0.20 eV, 0.33 eV, 0.41 eV and 1.71 eV, respectively. Besides, g-C2O membrane exhibits high He selectivity towards other gas molecules in a wide range of temperatures. The MD simulation results demonstrate that the He permeance of g-C2O membrane is as high as 1.03 × 107 GPU at room temperature (300 K). Therefore, in terms of He selectivity and permeance, g-C2O membrane is an excellent helium separation membrane.