Transparent proton transport through a two-dimensional nanomesh material.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31481679.
- Also identified by DOI 10.1038/s41467-019-11899-y and PMC identifier 6722077.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Molecular sieving is of great importance to proton exchange in fuel cells, water desalination, and gas separation. Two-dimensional crystals emerge as superior materials showing desirable molecular permeability and selectivity. Here we demonstrate that a graphdiyne membrane, an experimentally fabricated member in the graphyne family, shows superior proton conductivity and perfect selectivity thanks to its intrinsic nanomesh structure. The trans-membrane hydrogen bonds across graphdiyne serve as ideal channels for proton transport in Grotthuss mechanism. The free energy barrier for proton transfer across graphdiyne is ~2.4 kJ mol<sup>-1</sup>, nearly identical to that in bulk water (2.1 kJ mol<sup>-1</sup>), enabling "transparent" proton transport at room temperature. This results in a proton conductivity of 0.6 S cm<sup>-1</sup> for graphdiyne, four orders of magnitude greater than graphene. Considering its ultimate pore size of 0.55 nm, graphdiyne membrane blocks soluble fuel molecules and exhibits superior proton selectivity. These advantages endow graphdiyne a great potential as proton exchange material.