General Approach to Individually Dispersed, Highly Soluble, and Conductive Graphene Nanosheets Functionalized by Nitrene Chemistry

A unified approach to covalently functionalize graphene nanosheets based on nitrene chemistry is reported. This strategy is simple and efficient, allowing various functional moieties (e.g., hydroxyl, carboxyl, amino, bromine, long alkyl chain, etc.) and polymers (e.g., poly(ethylene glycol), polystryene) to covalently and stably anchor on graphene to produce single-layer functionalized graphene from graphene oxide in a one-step reaction. The structure and morphology of nanosheets are characterized using microscopy (AFM, SEM, TEM), spectroscopy (FTIR, XPS, Raman), thermal gravimetric analysis (TGA), and X-ray diffraction (XRD) measurements. The resulting functionalized graphene nanosheets are electrically conductive, readily dispersible in solvents and easily processable, making them promising candidates for further modification and applications such as nanohybrids, and polymer composites, etc. The presented work provides a general methodology to prepare individually dispersed graphene nanosheets with various functionalizations and properties, paving the way for the synthesis and applications of functionalized graphene materials.