Selective Permeation Through One-Atom-Thick Nanoporous Carbon Membranes: Theory Reveals Excellent Design Strategies!

Research on the permeation of various species through one-atom-thick nanoporous carbon membranes has gained an unprecedented importance in the past decade, thanks to the development of numerous theoretical design strategies for a plethora of applications ranging from gas separation, water desalination, isotope separation, and chiral separation, to DNA sequencing. Although some of the recent experiments have demonstrated successful performance of such carbon membranes in sieving, many of the suggested applications are yet to be realized in experiments. This review aims to draw the attention of the theoretical as well as the experimental researchers working on two-dimensional carbon materials toward the recent theoretical developments probing the permeation of various species such as atoms, ions, small molecules, and biopolymers like DNA through carbon frameworks like graphynes, graphdiyne, graphenylenes, and various forms of nanoporous graphene, including graphene crown ethers. The underlying guiding principles toward the design of carbon-based membranes for nanofiltration are established using estimates of the adsorption energies, barrier heights for permeation, rates of permeation, selectivities, permeances, etc. The crucial roles of tunneling, temperature effects, chemical functionalities, and dynamical aspects of the nanopores are also highlighted, paving the way to a comprehensive description of the theoretical design strategies for tailoring the applicability of novel nanoporous carbon membranes in sieving and related aspects.