title: Slide fastener reduction of graphene-oxide edges by calcium: insight from ab initio molecular dynamics.
abstract: The reduction of graphene oxide can be used as a simple way to produce graphene on a large scale. However, the numerous edges produced by the oxidation of graphite seriously degrade the quality of the graphene and its carrier transport property. In this work, the reduction of oxygen-passivated graphene edges and the subsequent linking of separated graphene sheets by calcium are investigated by using first-principles calculations. The calculations show that calcium can effectively remove the oxygen groups from two adjacent edges. The joining point of the edges serves as the starting point of the reduction and facilitates the reaction. Once the oxygen groups are removed, the crack is sutured. If the joining point is lacking, it becomes difficult to zip the separated fragments. A general electron-reduction model and a random atom-reduction model are suggested for these two situations. The present study sheds light on the reduction of graphene-oxide edges by using reactive metals to give large-sized graphene through a simple chemical reaction.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (PR China), Fax: (+86) 431 85168281.
authors.forename: Sheng-Yi
authors.initials: SY
authors.lastname: Xie
authors.forename: Xian-Bin
authors.initials: XB
authors.lastname: Li
authors.forename: Wei Quan
authors.initials: WQ
authors.lastname: Tian
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Nian-Ke
authors.initials: NK
authors.lastname: Chen
authors.forename: Dong
authors.initials: D
authors.lastname: Han
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Sun
keywords: ab initio calculations; edge; electron transfer; graphene oxide; metal reduction