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.