Selective Liquid‐Phase Extraction of Carboxylate‐Rich Graphene Quantum Dots from Graphene Oxide Dispersions

Abstract

An advanced simple synthetic route for graphene quantum dots (GQDs) is great importance to progress from laboratory research to industrial applications. Unfortunately, the existing state of synthesis methods of carboxylic acid‐rich GQDs needs additional reaction steps including oxidation, hydro‐ or solvo‐thermal reaction with bulk carbon sources. Besides, its yield is too low compared to starting amount of carbon sources due to complicated purification processes. Hence, production expense is inevitably increased to obstacle actual industrial applications. Here, we report a new synthetic method based on the liquid‐phase extraction technique to separate carboxylate‐rich GQDs (CGQDs) with high yield (> 30%) from graphene oxide (GO) dispersions without additional oxidation and purification processes.

A Practical Guide to Prepare and Synthetically Modify Graphene Quantum Dots

“…The two most prominent techniques for the physical characterization of GQDs are transmission electron microscopy (TEM) and AFM . These microscopy techniques are now widespread among materials and chemistry laboratories and can be used to accurately measure the diameter (TEM) and height (AFM for the number of graphitic layers) of GQDs . TEM can also be used to assess the crystallinity of formed GQDs and is perhaps the more accessible of the two techniques in terms of ease of operation …”