Seed/catalyst-free growth of zinc oxide nanostructures on multilayer graphene by thermal evaporation

Ahmad, Nurul Fariha; Rusli, Nurul Izni; Mahmood, Mohamad Rusop; Yasui, Kanji; Hashim, Abdul Manaf

doi:10.1186/1556-276x-9-83

Cited by 23 publications

(35 citation statements)

References 35 publications

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“…In recent years, the hybrid structures of zinc oxide (ZnO) nanostructures on graphene have attracted much attention because the nanostructures can offer additional functionalities to graphene for realizing advanced nanoscale applications [ 1 , 2 ]. This is due to the superior properties of nanostructures such as quantum confinement effects and high surface-to-volume ratio [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of zinc oxide nanostructures on graphene/glass substrate by electrochemical deposition: effects of current density and temperature

et al. 2014

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The electrochemical growth of zinc oxide (ZnO) nanostructures on graphene on glass using zinc nitrate hexahydrate was studied. The effects of current densities and temperatures on the morphological, structural, and optical properties of the ZnO structures were studied. Vertically aligned nanorods were obtained at a low temperature of 75°C, and the diameters increased with current density. Growth temperature seems to have a strong effect in generating well-defined hexagonal-shape nanorods with a smooth top edge surface. A film-like structure was observed for high current densities above -1.0 mA/cm2 and temperatures above 80°C due to the coalescence between the neighboring nanorods with large diameter. The nanorods grown at a temperature of 75°C with a low current density of -0.1 mA/cm2 exhibited the highest density of 1.45 × 109 cm-2. X-ray diffraction measurements revealed that the grown ZnO crystallites were highly oriented along the c-axis. The intensity ratio of the ultraviolet (UV) region emission to the visible region emission, IUV/IVIS, showed a decrement with the current densities for all grown samples. The samples grown at the current density below -0.5 mA/cm2 showed high IUV/IVIS values closer to or higher than 1.0, suggesting their fewer structural defects. For all the ZnO/graphene structures, the high transmittance up to 65% was obtained at the light wavelength of 550 nm. Structural and optical properties of the grown ZnO structures seem to be effectively controlled by the current density rather than the growth temperature. ZnO nanorod/graphene hybrid structure on glass is expected to be a promising structure for solar cell which is a conceivable candidate to address the global need for an inexpensive alternative energy source.

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Section: Introductionmentioning

confidence: 99%

Synthesis of zinc oxide nanostructures on graphene/glass substrate by electrochemical deposition: effects of current density and temperature

et al. 2014

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“…[185][186][187][188][189][190] Most studies on the ZnO/graphene hybrid structures have been focused on their structural morphology and electronic properties. 191,192 Recently, Xiang et al 193 rst proposed a three-component composite, TiO 2 /graphene/MoS 2 , containing 0.25 wt% graphene. The results showed that graphene acts as an electron reservoir and MoS 2 can act as a source of active adsorption sites to achieve a highly efficient synergetic H 2 evolution at the rate of 165.3 mmol h À1 , which is 17 times that of TiO 2 /MoS 2 .…”

Section: Theoretical Achievements For the Development Of Nanophotocatmentioning

confidence: 99%

“…Many studies have been conducted on the development of semiconducting material/graphene hybrid structures using either gas phase [223][224][225][226] or liquid phase techniques. 185,186,191,227 Hou et al 228 have developed a CdS QDs/graphene/ZnIn 2 S 4 system that exhibits highly efficient H 2 production due to the high hydrothermal stability and efficient electron transfer. Graphene can also play a role as a co-catalyst and constitutes a synergistic effect with the other co-catalyst to improve the photocatalytic efficiency.…”

Section: Theoretical Achievements For the Development Of Nanophotocatmentioning

confidence: 99%

Nanomaterials for photocatalytic hydrogen production: from theoretical perspectives

Bhatt

Lee

2017

RSC Adv.

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“…With this regard, the growth of Ga-based compound materials on graphene seems to be feasible. Recently, we have demonstrated the growth of several kinds of materials such as germanium (Ge) thin film [29], silicon carbide (SiC) thin film [30], and zinc oxide (ZnO) nanostructures [31][32][33][34][35] with considerably good properties directly on graphene without any use of seed or catalyst.…”

Section: Introductionmentioning

confidence: 99%

Seed/Catalyst-Free Growth of Gallium-Based Compound Materials on Graphene on Insulator by Electrochemical Deposition at Room Temperature

Wong¹,

Ali²,

Yasui³

et al. 2016

Nano Online

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We report the growth of gallium-based compounds, i.e., gallium oxynitride (GaON) and gallium oxide (Ga 2 O 3) on multilayer graphene (MLG) on insulator using a mixture of ammonium nitrate (NH 4 NO 3) and gallium nitrate (Ga(NO 3) 3) by electrochemical deposition (ECD) method at room temperature (RT) for the first time. The controlling parameters of current density and electrolyte molarity were found to greatly influence the properties of the grown structures. The thicknesses of the deposited structures increase with the current density since it increases the chemical reaction rates. The layers grown at low molarities of both solutions basically show grain-like layer with cracking structures and dominated by both Ga 2 O 3 and GaON. Such cracking structures seem to diminish with the increases of molarities of one of the solutions. It is speculated that the increase of current density and ions in the solutions helps to promote the growth at the area with uneven thicknesses of graphene. When the molarity of Ga(NO 3) 3 is increased while keeping the molarity of NH 4 NO 3 at the lowest value of 2.5 M, the grown structures are basically dominated by the Ga 2 O 3 structure. On the other hand, when the molarity of NH 4 NO 3 is increased while keeping the molarity of Ga(NO 3) 3 at the lowest value of 0.8 M, the GaON structure seems to dominate where their cubic and hexagonal arrangements are coexisting. It was found that when the molarities of Ga(NO 3) 3 are at the high level of 7.5 M, the grown structures tend to be dominated by Ga 2 O 3 even though the molarity of NH 4 NO 3 is made equal or higher than the molarity of Ga(NO 3) 3. When the grown structure is dominated by the Ga 2 O 3 structure, the deposition process became slow or unstable, resulting to the formation of thin layer. When the molarity of Ga(NO 3) 3 is increased to 15 M, the nanocluster-like structures were formed instead of continuous thin film structure. This study seems to successfully provide the conditions in growing either GaON-dominated or Ga 2 O 3-dominated structure by a simple and low-cost ECD. The next possible routes to convert the grown GaON-dominated structure to either single-crystalline GaN or Ga 2 O 3 as well as Ga 2 O 3-dominated structure to single-crystalline Ga 2 O 3 structure have been discussed.

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Seed/catalyst-free growth of zinc oxide nanostructures on multilayer graphene by thermal evaporation

Cited by 23 publications

References 35 publications

Synthesis of zinc oxide nanostructures on graphene/glass substrate by electrochemical deposition: effects of current density and temperature

Synthesis of zinc oxide nanostructures on graphene/glass substrate by electrochemical deposition: effects of current density and temperature

Nanomaterials for photocatalytic hydrogen production: from theoretical perspectives

Seed/Catalyst-Free Growth of Gallium-Based Compound Materials on Graphene on Insulator by Electrochemical Deposition at Room Temperature

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