title: Coal as an abundant source of graphene quantum dots.
abstract: Coal is the most abundant and readily combustible energy resource being used worldwide. However, its structural characteristic creates a perception that coal is only useful for producing energy via burning. Here we report a facile approach to synthesize tunable graphene quantum dots from various types of coal, and establish that the unique coal structure has an advantage over pure sp2-carbon allotropes for producing quantum dots. The crystalline carbon within the coal structure is easier to oxidatively displace than when pure sp2-carbon structures are used, resulting in nanometre-sized graphene quantum dots with amorphous carbon addends on the edges. The synthesized graphene quantum dots, produced in up to 20% isolated yield from coal, are soluble and fluorescent in aqueous solution, providing promise for applications in areas such as bioimaging, biomedicine, photovoltaics and optoelectronics, in addition to being inexpensive additives for structural composites.
authors.affiliation: 1] Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA [2].
authors.forename: Ruquan
authors.initials: R
authors.lastname: Ye
authors.forename: Changsheng
authors.initials: C
authors.lastname: Xiang
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Peng
authors.forename: Kewei
authors.initials: K
authors.lastname: Huang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yan
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Cook
authors.forename: Errol L G
authors.initials: EL
authors.lastname: Samuel
authors.forename: Chih-Chau
authors.initials: CC
authors.lastname: Hwang
authors.forename: Gedeng
authors.initials: G
authors.lastname: Ruan
authors.forename: Gabriel
authors.initials: G
authors.lastname: Ceriotti
authors.forename: Abdul-Rahman O
authors.initials: AR
authors.lastname: Raji
authors.forename: Angel A
authors.initials: AA
authors.lastname: Martí
authors.forename: James M
authors.initials: JM
authors.lastname: Tour
mesh_terms: D002244:Carbon / Q000737:chemistry; D003031:Coal; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D045663:Quantum Dots; D013696:Temperature
chemical_list: D003031:Coal; D002244:Carbon; D006108:Graphite