To: 02/12/2020 14:00
One of the most promising potential applications of porous graphene has been that of membrane for gas separation. In this presentation, we include an introductory review of this topic both experimentally and theoretically, showing attempts to overcome a main obstacle in creating useful devices. We then present our theoretical work which concerns the permeation of several molecular systems through pores in single layer graphene with the goal to determine the size and type of pores with optimal permeability and selectivity.
Our study was performed at the level of DFT (hybrid-meta GGA functionals). We particularly focused on pores that are created by carbon vacancies and nitrogen doping (pyridinic, pyrrolic defects). We demonstrate that the size of interest for gas separation is 0.5 nm and show examples of pores with industrially acceptable permeance that can effectively separate gases. Finally, we turn our attention to pore stacking in bilayer graphene which are studied with atomistic simulations. We show that combinations of pores can be used to control molecular permeability.