Charge-modulated permeability and selectivity in graphdiyne for hydrogen purification

Using first-principle calculations, we show that injecting positive charges into graphdiyne can substantially improve its hydrogen purification capability. When positive charges are introduced, the H2 penetration barrier decreases while the penetration barriers of CO and CH4 are significantly increased, hence leading to enhanced permeability and selectivity for hydrogen purification from CO and CH4. These predictions show that application of positive charge provides a unique pathway, which avoids complicated synthesis routes, to enhance hydrogen purification performance, and may prove to be instrumental in searching for a new class of high-permeability and high-selectivity molecular-sieving membranes.