title: Catalyst-Free Growth of Three-Dimensional Graphene Flakes and Graphene/g-C₃N₄ Composite for Hydrocarbon Oxidation.
abstract: Mass production of high-quality graphene flakes is important for commercial applications. Graphene microsheets have been produced on an industrial scale by chemical and liquid-phase exfoliation of graphite. However, strong-interaction-induced interlayer aggregation usually leads to the degradation of their intrinsic properties. Moreover, the crystallinity or layer-thickness controllability is not so perfect to fulfill the requirement for advanced technologies. Herein, we report a quartz-powder-derived chemical vapor deposition growth of three-dimensional (3D) high-quality graphene flakes and demonstrate the fabrication and application of graphene/g-C3N4 composites. The graphene flakes obtained after the removal of growth substrates exhibit the 3D curved microstructure, controllable layer thickness, good crystallinity, as well as weak interlayer interactions suitable for preventing the interlayer stacking. Benefiting from this, we achieved the direct synthesis of g-C3N4 on purified graphene flakes to form the uniform graphene/g-C3N4 composite, which provides efficient electron transfer interfaces to boost its catalytic oxidation activity of cycloalkane with relatively high yield, good selectivity, and reliable stability.
authors.affiliation: Key Laboratory for Special Functional Materials of Ministry of Education, Henan University , Kaifeng 475004, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chai
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.forename: Liurong
authors.initials: L
authors.lastname: Shi
authors.affiliation: CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology , Beijing 100190, People's Republic of China.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Liu
authors.forename: Qin
authors.initials: Q
authors.lastname: Xie
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Xu
authors.affiliation: Department of Aerospace and Mechanical Engineering, West Virginia University , Morgantown, West Virginia 26507, United States.|NETL, U.S. Department of Energy , Morgantown, West Virginia 26507, United States.
authors.forename: Ayyakkannu
authors.initials: A
authors.lastname: Manivannan
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu
keywords: chemical vapor deposition; g-C3N4; graphene; powder; three-dimensional