Thermochemical functionalisation of graphenes with minimal framework damage

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Graphene and graphene nanoplatelets offer unique properties but often require surface modification for specific applications.
• Existing functionalization methods can introduce defects or are difficult to scale.
• Developing scalable and defect-minimizing functionalization techniques is crucial for widespread graphene utilization.

Purpose of the Study:

• To develop and demonstrate a versatile, scalable, gas-phase thermochemical method for functionalizing graphene and graphene nanoplatelets.
• To confirm the covalent modification and preservation of lattice integrity in functionalized graphene.
• To showcase the applicability of the method to bulk graphene nanoplatelets and create various derivatives.

Main Methods:

• Gas-phase thermochemical functionalization applied to single-layer graphene and bulk graphene nanoplatelets.
• Characterization using Transmission Electron Microscopy (TEM) for direct imaging of covalent modification.
• Analysis via Raman spectrometry, Atomic Force Microscopy (AFM) nano-indentation, Thermogravimetric Analysis (TGA), and X-ray Photoelectron Spectroscopy (XPS) to confirm functionalization and assess properties.

Main Results:

• Direct TEM imaging confirmed covalent grafting on single-layer graphene without lattice damage.
• Raman spectrometry and AFM nano-indentation verified the mechanical integrity of functionalized graphene.
• Successful preparation of anionic, cationic, and non-ionic derivatives from bulk graphene nanoplatelets, evidenced by TGA, Raman, XPS, and improved aqueous dispersibility.

Conclusions:

• Gas-phase thermochemical functionalization is a versatile and scalable method for modifying graphene and graphene nanoplatelets.
• The approach effectively introduces covalent modifications without compromising the structural integrity of the graphene lattice.
• This facile technique, adaptable to Chemical Vapor Deposition (CVD) equipment, enables tailored functionalization of diverse graphene-related nanocarbons.