title: Bandgap engineering of coal-derived graphene quantum dots.
abstract: Bandgaps of photoluminescent graphene quantum dots (GQDs) synthesized from anthracite have been engineered by controlling the size of GQDs in two ways: either chemical oxidative treatment and separation by cross-flow ultrafiltration, or by a facile one-step chemical synthesis using successively higher temperatures to render smaller GQDs. Using these methods, GQDs were synthesized with tailored sizes and bandgaps. The GQDs emit light from blue-green (2.9 eV) to orange-red (2.05 eV), depending on size, functionalities and defects. These findings provide a deeper insight into the nature of coal-derived GQDs and demonstrate a scalable method for production of GQDs with the desired bandgaps.
authors.forename: Ruquan
authors.initials: R
authors.lastname: Ye
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Peng
authors.forename: Andrew
authors.initials: A
authors.lastname: Metzger
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.forename: Jason A
authors.initials: JA
authors.lastname: Mann
authors.forename: Kewei
authors.initials: K
authors.lastname: Huang
authors.forename: Changsheng
authors.initials: C
authors.lastname: Xiang
authors.affiliation: ||College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124, China.
authors.forename: Xiujun
authors.initials: X
authors.lastname: Fan
authors.forename: Errol L G
authors.initials: EL
authors.lastname: Samuel
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Alemany
authors.forename: Angel A
authors.initials: AA
authors.lastname: Martí
authors.forename: James M
authors.initials: JM
authors.lastname: Tour
keywords: anthracite; bandgap; cross-flow filtration; graphene quantum dots; photoluminescent