Identifying optimal GO membranes for H₂O/H₂O₂ separation through molecular dynamics simulations

Designing high-performance membrane for the purification of hydrogen peroxide (H2O2) relies on an in-depth understanding of underlying separation mechanism. Herein, the microscopic mechanisms of separating H2O/ H2O2 in different graphene oxide (GO) membranes are unraveled by means of molecular dynamics (MD) simulations. The effects of interlayer spacing (H), membrane thickness (L) and O/C ratio (R) on H2O permeability and H2O/H2O2 selectivity are analyzed, and it's found the membranes with H = 9 angstrom generally display excellent performance. In addition, optimal membrane structures (L40-H9-20%, and L30-H9-40%) for outstanding H2O/ H2O2 separation performance are identified, toward which two separation mechanisms are proposed: at low O/C ratio, the molecular diffusibility is dominant, and the L40-H9-20% membrane achieves the H2O permeability of 69.0 kg center dot m(-2)center dot s(-1) and the H2O/H2O2 selectivity of 6.93; at high O/C ratio, the molecular steric effect is dominant, and the L30-H9-40% membrane shows the H2O permeability of 27.7 kg center dot m 2 center dot s 1 and H2O/H2O2 selectivity of 10.12. This study provides theoretical guidance on the preparation of high-performance membranes for H2O/ H2O2 separation.