Enhanced Hydrogen Purification in Nanoporous Phosphorene Membrane with Applied Electric Field

As a feasibility study for hydrogen purification, the mechanisms of H₂, CO₂, N₂, CO, and CH₄ penetrating through self-passivated porous phosphorene membranes with different pore sizes were systematically investigated by density functional theory. The thermal stability of porous phosphorene membranes with various pore sizes was studied by ab initio molecular dynamics. By applying an external electric field perpendicular to the porous phosphorene membrane, the diffusion of CO₂ and N₂ through the pores was remarkably suppressed due to the polarizability of these molecules, whereas the energy barrier and permeance of H₂ passing through the membrane is virtually unaffected. Thus, the application of the electric field improves the performance of hydrogen purification further. This finding opens up a new avenue to optimally tune the performance of 2D materials for gas separation by applying an external electric field.