title: Seedless growth of zinc oxide flower-shaped structures on multilayer graphene by electrochemical deposition.
abstract: A seedless growth of zinc oxide (ZnO) structures on multilayer (ML) graphene by electrochemical deposition without any pre-deposited ZnO seed layer or metal catalyst was studied. A high density of a mixture of vertically aligned/non-aligned ZnO rods and flower-shaped structures was obtained. ML graphene seems to generate the formation of flower-shaped structures due to the stacking boundaries. The nucleation of ZnO seems to be promoted at the stacking edges of ML graphene with the increase of applied current density, resulting in the formation of flower-shaped structures. The diameters of the rods/flower-shaped structures also increase with the applied current density. ZnO rods/flower-shaped structures with high aspect ratio over 5.0 and good crystallinity were obtained at the applied current densities of -0.5 and -1.0 mA/cm(2). The growth mechanism was proposed. The growth involves the formation of ZnO nucleation below 80°C and the enhancement of the growth of vertically non-aligned rods and flower-shaped structures at 80°C. Such ZnO/graphene hybrid structure provides several potential applications in sensing devices.
authors.affiliation: Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Semarak, Kuala Lumpur 54100, Malaysia.
authors.forename: Nur Suhaili Abd
authors.initials: NS
authors.lastname: Aziz
authors.affiliation: Department of Electrical Engineering, Nagaoka University of Technology, Kamitomioka-machi, Nagaoka, Niigata 940-2137, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nishiyama
authors.affiliation: Faculty of Engineering Technology, Universiti Malaysia Perlis, Uniciti Campus Sungai Chucuh, Padang Besar, Perlis 02100, Malaysia.
authors.forename: Nurul Izni
authors.initials: NI
authors.lastname: Rusli
authors.affiliation: Faculty of Electrical Engineering, Universiti Teknologi MARA, Shah Alam, Selangor 40540, Malaysia.
authors.forename: Mohamad Rusop
authors.initials: MR
authors.lastname: Mahmood
authors.affiliation: Department of Electrical Engineering, Nagaoka University of Technology, Kamitomioka-machi, Nagaoka, Niigata 940-2137, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Yasui
authors.affiliation: Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Semarak, Kuala Lumpur 54100, Malaysia ; MIMOS Berhad, Technology Park Malaysia, Kuala Lumpur 47000, Malaysia.
authors.forename: Abdul Manaf
authors.initials: AM
authors.lastname: Hashim
keywords: Electrochemical deposition; Flower-shaped structure; Graphene; Rod; Zinc oxide