Nanoscale Structural and Electronic Properties of Cellulose/Graphene Interfaces

TL;DR

This study provides a detailed theoretical analysis of cellulose/graphene interfaces, revealing their structural, electronic, and tunable properties crucial for developing advanced bio-based electronic devices.

Contribution

It offers the first atomistic insights into the binding, electronic structure, and tunability of cellulose/graphene interfaces, including effects of solvation, strain, and electric fields.

Findings

Van der Waals interactions dominate binding energies.

Aqueous media reinforce the hydrophobic interface stability.

External electric fields and strain can tune the Dirac cone and charge density.

Abstract

The development of electronic devices based on the functionalization of (nano)cellulose platforms relies upon an atomistic understanding of the structural, and electronic properties of the combined system, cellulose/functional element. In this work, we present a theoretical study of the nanocellulose/graphene interface (nCL/G) based on first-principles calculations. We find that the binding energies of both hydrophobic/G (nCL$^{\rm phob}$/G) and hydrophilic/G (nCL$^{\rm phil}$/G) interfaces are primarily dictated by the van der Waals interactions, and are comparable with that of their 2D interface counterparts. We verify that the energetic preference of nCL$^{\rm phob}$/G has been reinforced by the inclusion of an aqueous media via the implicit solvation model. Further structural characterization was carried out using a set of simulations of Carbon K-edge X-ray absorption spectra to identify and distinguish the key absorption features of the nCL$^{\rm phob}$/G and nCL$^{\rm phil}$/G interfaces. The electronic structure calculations reveal that the linear energy bands of graphene lie in the band gap of the nCL, sheet, while depletion/accumulation charge density regions are observed. We show that external agents, i.e. electric field and mechanical strain, allow for tunability of the Dirac cone and the charge density at the interface. The control/maintenance of the Dirac cone states in nCL/G is an important feature for the development of electronic devices based on cellulosic platforms.