Preferential functionalization on zigzag graphene nanoribbons: First-principles calculations

TL;DR

This study uses first-principles calculations to show that functional groups preferentially attach to zigzag edges of graphene nanoribbons over armchair edges, enabling selective functionalization based on edge type.

Contribution

It demonstrates the energetic preference for functionalization on zigzag edges and identifies conditions for selective attachment, advancing potential separation techniques.

Findings

Functionalization energy lower on zigzag edges by ~0.2 eV.

Structural deformation occurs on armchair edges but not on zigzag edges.

Selective functionalization feasible at ~25°C and 10^-5 atm.

Abstract

We investigate the functionalization of functional groups to graphene nanoribbons with zigzag and armchair edges using first principles calculations. We find that the formation energy for the configuration of the functional groups functionalized to the zigzag edge is ~0.2 eV per functional group lower than that to the armchair edge. The formation energy difference arises from a structural deformation on the armchair edge by the functionalization whereas there is no structural deformation on the zigzag edge. Selective functionalization on the zigzag edge takes place at a condition of the temperature and the pressure of ~25 oC and 10-5 atm. Our findings show that the selective functionalization can offer the opportunity for an approach to the separation of zigzag graphene nanoribbons with their solubility change.