Covalent Crosslinking of Graphene Quantum Dots by McMurry Deoxygenation Coupling.
Graphene quantum dots were covalently crosslinked forming ensembles of a few hundred nanometers in size by McMurry deoxygenation coupling reactions of peripheral carbonyl functional moieties catalyzed by TiCl4and Zn powders in refluxing THF, as evidenced by TEM, AFM, FTIR, Raman and XPS measurements. Photoluminescence measurements showed that after chemical coupling, the excitation and emission peaks blue-shifted somewhat and the emission intensity increased markedly, likely due to the removal of oxygenated species where quinone-like species are known to be effective electron acceptors and emission quenchers.
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA.
Limei
L
Chen
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA.
Peiguang
P
Hu
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA.
Jia En
JE
Lu
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA.
Shaowei
http://orcid.org/0000-0002-3668-8551
S
Chen
McMurry deoxygenation coupling; covalent crosslinking; graphene quantum dots; oxygenated moiety; photoluminescence