Functionalization of Graphene via 1,3-Dipolar Cycloaddition

Abstract

Few-layer graphenes (FLG) produced by dispersion and exfoliation of graphite in N-methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV-vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal C horizontal lineC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.

Experimental Sensing and Density Functional Theory Study of H2S and SOF2 Adsorption on Au‐Modified Graphene

“…Moreover, the C 1s spectrum can be fitted into four peaks corresponding to C atoms from four functional groups: nonoxygenated ring C at 284.8 eV, C in the C—N bond at 285.8 eV, hydroxyl C at 286.8 eV, and carbonyl C at 288.6 eV. After Au was introduced, a new peak appears at 284.2 eV and this peak is attributed to the C—N—Au bond 26, 27, 28. After peak‐differentiation‐imitating analysis, the Au 4f doublet deconvolutes into two pairs of peaks, which correspond to the reduced Au (0) at 84.27 eV in Au 4f 7/2 and at 87.94 eV in Au 4f 5/2 , Au (III) ions at 85.02 eV in Au 4f 7/2 and Au (I) ions at 88.37 eV in Au 4f 5/2 , respectively 29.…”

The Prospective Two-Dimensional Graphene Nanosheets: Preparation, Functionalization and Applications

“…Through chemical reduction of GO by reducing reagents or thermal treatment, the covalently functionalized graphene can be formed, resulting in a much better dispersity in water or organic solvents. In order to enhance the hydrophilicity or lipophilicity of graphene, some small molecules and polymers, can be introduced to the plane of graphene, through radical addition reaction [32], cycloaddition reaction [33], or diazonium salts reaction [34] during the in situ reduction of GO into graphene. As a result, this would lead to a much better dispersity of graphene in water or organic solvents.…”

Janus graphene from asymmetric two-dimensional chemistry

“…Physisorption of chemical species on graphene would provide a facile way to alter its electronic properties 12 , however, covalent chemical modification shows a great advantage in achieving permanent stabilisation for long-term usage 13 . Previous attempts towards fundamental research on covalent functionalisation of graphene mainly involved the development of new modification strategies (for example, hydrogenation [14][15][16][17] , fluorination [18][19][20] , chlorination 21,22 , diazotization [23][24][25][26][27] and other cycloaddition reactions [28][29][30][31] ), covalent addition of edge and defects 27,32 , fabrication of chemical superlattices 26,33 and quantum effects in graphene modification 17,34 . Of the various significant research activities on graphene chemistry that have been conducted, nearly no work to date has been focused on the asymmetric chemistry of this ideal 2D atomic crystal via covalently attaching different functional groups on its two faces simultaneously.…”