Simulation Analysis of Enhanced Ion Selectivity in a Single Graphene Nanopore

In recent years, asymmetric graphene nanochannels have become one of the trustworthy options for many applications. However, further research on the mechanisms of graphene nanochannels is still needed. In this work, we systematically investigated the ion selectivity of single graphene nanopore models using finite element simulation techniques. Results from the simulations reveal that graphene can substantially improve the ion selectivity of asymmetric nanochannels, and the ion selectivity ratio of the single graphene nanopore supported by the conical nanochannel is about 2 orders of magnitude higher than the ion selectivity ratio of the model without graphene. Moreover, we provided reasonable insight into the mechanism of ion selectivity: the ion selectivity of the graphene nanopore supported by the conical nanochannel can be attributed to the concentration differences between cations and anions at the tip.