title: Facile preparation of nitrogen-doped few-layer graphene via supercritical reaction.
abstract: To achieve the applications of graphene, the modulation of its electrical properties is of great significance. The element doping might give a promising approach to produce fascinating properties of graphene. Herein we report a facile chemical doping method to obtain nitrogen-doped (N-doped) few-layer graphene sheets through supercritical (SC) reaction in acetonitrile at temperature as low as 310 °C, using expanded graphite as starting material. X-ray photoelectron spectroscopy analysis revealed that the level of nitrogen-doping (N-doping) increased from 1.57 to 4.56 at % when the reaction time was tuned from 2 to 24 h. Raman spectrum confirmed that the resulting N-doped few-layer graphene by SC reaction maintain high quality without any significant structural defects. Electrical measurements indicated that N-doped few-layer graphene sheets exhibit a typical n-type field-dependent behavior, suggesting the N-doping into the lattice of graphene. This work provides a convenient chemical route to the scalable production of N-doped graphene for potential applications in nanoelectronic devices.
authors.affiliation: Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Qian
authors.forename: Xu
authors.initials: X
authors.lastname: Cui
authors.forename: Rui
authors.initials: R
authors.lastname: Hao
authors.forename: Yanglong
authors.initials: Y
authors.lastname: Hou
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang