Propagative Exfoliation of High Quality Graphene

通讯作者地址: Deng, SL (通讯作者) Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China. [email protected]; [email protected] quality graphene materials that readily disperse in water or organic solvents are needed to achieve some of the most ambitious applications. However, current synthetic approaches are typically limited by irreversible structural damages, little solubility, or low scalability. Here, we describe a fundamental study of graphene chemistry and covalent functionalization patterns on sp(2) carbon lattices, from which a facile, scalable synthesis of high quality graphene sheets was developed. Graphite materials were efficiently exfoliated by reductive, propagative alkylation. The exfoliated, propagatively alkylated graphene sheets (PAGenes) not only exhibited high solubility in common solvents such as chloroform, water, and N-methyl-pyrrolidone, but also showed electrical conductivity as high as 4.1 X 10(3) S/m, which is 5 orders of magnitude greater than those of graphene oxides. Bright blue photoluminescence, unattainable in graphene, was also observed. We attribute the rise of blue photoluminescence in PAGenes to small on-graphene sp(2) domains created by the propagative covalent chemistry, which may expand from graphene edges or existing defect sites leaving sp(2)-hybridized patches interlaced with sp(3)-hybridized regions. The intact sp(2) domains enable effective electrical percolation among different graphene layers affording the observed high electrical conductivity in PAGene films.National Key Basic Research Program of China 2013CB933901 National Natural Science Foundation of China 21171140 21021061 21031004 U1205111 Natural Science Foundation of Fujian Province of China 2013J01056 Fundamental Research Funds for the Central Universities University of Maryland U.S. National Science Foundation CAREER CHE-105551