Graphdiyne based membranes: exceptional performances for helium separation applications

TL;DR

This paper demonstrates that graphdiyne membranes exhibit exceptional helium separation capabilities, surpassing existing membranes in selectivity and enabling potential isotopic separation of helium isotopes at low temperatures.

Contribution

It introduces the use of graphdiyne as a membrane material for helium separation, highlighting its superior selectivity and potential for isotopic separation based on tunneling differences.

Findings

High He/CH_4 selectivity exceeding current membranes

Effective separation of ^3He and ^4He isotopes at low temperatures

Potential for chemical and isotopic helium separation applications

Abstract

Graphdiyne is a novel two-dimensional material deriving from graphene that has been recently synthesized and featuring uniformly distributed sub-nanometer pores. We report accurate calculations showing that graphdiyne pores permit an almost unimpeded helium transport which can be used for its chemical and isotopic separation. Exceptionally high He/CH_4 selectivities are found which largely exceed the performance of the best membranes used to date for extraction from natural gas. Moreover, by exploiting slight differences in the tunneling probabilities of ^3He and ^4He, we also find promising results for the separation of the Fermionic isotope at low temperature.