On the physisorption of water on graphene: a CCSD(T) study

TL;DR

This study uses high-accuracy CCSD(T) quantum chemistry methods to investigate water adsorption on graphene, revealing stronger binding energies than standard DFT calculations and emphasizing the importance of dispersion interactions.

Contribution

It applies local correlation CCSD(T) methods to extended graphene systems, providing more accurate adsorption energies for water than traditional DFT approaches.

Findings

CCSD(T) predicts higher water-graphene binding energies than DFT.

Physisorption of water on graphene is confirmed with more accurate energies.

Results align with literature but show stronger interactions.

Abstract

The electronic structure of the zero-gap two-dimensional graphene has a charge neutrality point exactly at the Fermi level that limits the practical application of this material. There are several ways to modify the Fermi-level-region of graphene, e.g. adsorption of graphene on different substrates or different molecules on its surface. In all cases the so-called dispersion or van der Waals interactions can play a crucial role in the mechanism, which describes the modification of electronic structure of graphene. The adsorption of water on graphene is not very accurately reproduced in the standard density functional theory (DFT) calculations and highly-accurate quantum-chemical treatments are required. A possibility to apply wavefunction-based methods to extended systems is the use of local correlation schemes. The adsorption energies obtained in the present work by means of CCSD(T) are much higher in magnitude than the values calculated with standard DFT functional although they agree that physisorption is observed. The obtained results are compared with the values available in literature for binding of water on the graphene-like substrates.