Green and fast synthesis of amino-functionalized graphene quantum dots with deep blue photoluminescence

Determination of amino groups on functionalized graphene oxide for polyurethane nanomaterials: XPS quantitation vs. functional speciation

“…16 Amino-functionalized carbon materials (GO, CNTs, graphene, etc.) have found numerous applications as nanollers in polymer composites and coatings, 17 metal-free catalysts for oxygen reduction reactions, 18 photoluminescent materials 19 and materials for immobilization or release of biologically active molecules. 20 The amino groups are also responsible for the antimicrobial properties of the material, via their interaction with negatively charged cell walls.…”

One-Step Synthesis of Diamine-Functionalized Graphene Quantum Dots from Graphene Oxide and Their Chelating and Antioxidant Activities

“…In recent years, the functionalization of GQDs with amine groups has gained interest in tuning the electronic and optical properties of GQDs due to the strong interactions between the nitrogen atoms and the graphene network (orbital interactions between the nonbounded pair of electrons of N with the HOMO and LUMO orbitals at GQDs allowing for a narrowing of the bandgap) [26]. The synthesis of amine-functionalized GQDs is generally conducted at high temperature while using ammonia [11,28,[31][32][33][34] or urea [35], which react with epoxides, alcohols, and carboxylic acids groups that are present at the surface of oxidized graphene sheets to yield GQDs edge-terminated with primary amine functions.…”

Spectroanalytical Methods Using Graphene Quantum Dots as Photoluminescent Probes for the Determination of Analytes of Biological and Pharmacological Interest

“…The wide extinction spectrum, with a maximum peak at about 220 nm, is characteristic of semiconductor quantum dots. Spectral features can be attributed to π -π* transition of C=C of sp 2 carbon and to the presence of possible amino functional groups at the edge of the quantum dots [115]. The first excitonic band appeared at 345 nm ( Fig.…”

“…4.5C) at binding energy 399.8 eV, indicating that the nature of the nitrogen attached to the surface is mainly organic such as the ones typical of amines C-N. The second peak at 401.7 eV corresponds to graphitic bound N. Together with the significant changes in photoluminescence, those XPS spectral features strongly indicated the functionalization of GQDs edges and surface with nitrogen (most probably amino groups) that affects significantly photoluminescence and produced better dispersed nanostructures in water because of the creation of surface charges[115,117].…”