Graphene Derivatives: Controlled Properties, Nanocomposites, and Energy Harvesting Applications

Abstract

Graphene is a ground-breaking two-dimensional (2D) material that possesses outstanding electrical, optical, thermal, and mechanical properties and that promises a new generation of devices. Despite all these, some applications require graphene-based materials with different characteristics, such as good solubility in organic solvents and a specific band gap to be dispersible in polymer nanocomposite matrix and applied as active layer, electron transport layer (ETL) or hole transport layer (HTL) in organic photovoltaics. Chemically modified graphene derivatives are studied, searching for better dispersions and even more properties for different applications. Most of the attention has been drawn to dispersions of graphene oxides or highly reduced graphene oxides. Therefore, this allows an opportunity to study the characteristics of materials with intermediate oxidation degrees and its applications.

Antimicrobial Mechanisms and Effectiveness of Graphene and Graphene-Functionalized Biomaterials. A Scope Review

“…One of the main limitations is graphene's tendency to agglomerate due to its very low water dispersibility as a hydrophobic material in addition to its large surface area and high surface energy (Dreyer et al, 2010;Yang et al, 2014). To improve graphene's properties, chemical modifications were considered valuable approaches resulting in graphene derivatives which are applicable in different fields (Romero et al, 2017). Some examples are reported below.…”

“…Graphene oxide (GO) is the oxidized derivative of a graphene molecule, obtained by acid oxidation of graphite (Dreyer et al, 2010), i.e., it contains oxygen functional groups (hydroxyl, carboxyl, carbonyl, and epoxy). Thus, GO is an extremely hydrophilic molecule which is significantly beneficial in powerharvesting and electronic applications (Romero et al, 2017). The extreme hydrophilic properties of GO render these molecules insoluble in organic solvents such as alcohol, toluene, etc.…”

“…The extreme hydrophilic properties of GO render these molecules insoluble in organic solvents such as alcohol, toluene, etc. (Romero et al, 2017). Moreover, GO is an amorphous molecule with many defects that weaken its mechanical characteristics, rendering them much weaker than those of pristine graphene or reduced graphene oxide (Dreyer et al, 2010).…”

Anti-Infective and Toxicity Properties of Carbon Based Materials: Graphene and Functionalized Carbon Nanotubes

“…Graphene is a carbon layer of the graphite structure, composed of hybridized carbon atoms linked by longitudinal bonds tightly packed into a honeycomb lattice to form a two-dimensional crystal [80,81]. Graphene derivatives include graphene oxide (GO) and reduced graphene oxide (rGO), which are created by chemical modifications in graphene to improve its properties and can be used in various fields [82]. GO have oxygen functional groups including hydroxyl, carboxyl, carbonyl, and epoxy which are mostly obtained from an oxidized graphene molecule and graphite acid oxidation.…”

“…GO is insoluble in organic solvents such as alcohol, and toluene due to its strong hydrophilic properties. Furthermore, it is remarkably effective in force harvesting and electronic applications [82,83]. The GO structure includes many functional groups, which are capable of covalently binding to biological molecules and growth factors to strengthen cellular proliferation and differentiation.…”