Preparation of Few-Layer Graphene Dispersions from Hydrothermally Expanded Graphite

Abstract

In this study, we propose a novel approach to prepare few-layer graphene (FLG) dispersions, which is realized by exfoliating natural graphite flakes in a surfactant aqueous solution under hydrothermal treatment and liquid-phase exfoliation. In order to obtain stable and well-dispersed FLG dispersions, pristine graphite is hydrothermally expanded in a hexadecyltrimethylammonium bromide (CTAB) aqueous solution at 180 °C for 15 h, followed by sonication up to 3 h. In comparison to long-time sonication methods, the present method is significantly efficient, and most importantly, does not involve the use of an oxidizing agent and hazardous media, which will make it more competent in the scalable production of graphene.

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide

“…However, the q m = 121.95 mg g −1 is higher than previous studies (Table 4), suggesting that our green-prepared rGO is an excellent option for conventional materials. Although activated carbon seems to be more profitable to be used for the removal of MB [68] (Table 4), its adsorption equilibrium time (150 min) is higher compared to the present study (30 min), most importantly, rGO has a wide range of applications from composites to high frequency devices [21].…”

From 2D Graphene Nanosheets to 3D Graphene‐based Macrostructures

“…expanding the sonication time, raising the original concentration of graphite, introducing polymers, etc. In order to avoid graphene restacking during exfoliation, researchers have found that, with the aid of surfactants or dispersing agents, graphene sheets can be maintain in a good dispersion state after sonication …”

Facile Preparation of Multilayered Graphene with CO2 as a Carbon Source

“…Since the monolayer graphene was first obtained by Andre Geim and co-workers using the tape method [10], there has been increasing attention towards methods of such material preparation. The commonly applied methods include the micromechanical or chemical exfoliation of graphite, epitaxial growth on silicon carbide (SiC), chemical vapor deposition (CVD), as well as reduction of graphene oxide (GO) via chemical, electrochemical, thermal, or photocatalytic methods [11][12][13][14][15][16][17][18]. Among the above methods, a major focus of experimental research has been concentrated on the development of low-pollution preparation routes, enabling environmentally friendly production.…”