Feasibility of ZnO and Zn Seed Layers for Growth of Vertically Aligned and High-Quality ZnO Nanorods by the Sonochemical Method

2019 ◽  
Vol 290 ◽  
pp. 267-273
Author(s):  
Nama A. Hammed ◽  
Azlan Abdul Aziz ◽  
Adamu Ibrahim Usman

The role of both zinc oxide (ZnO) and zinc (Zn) seed layers were evaluated for the growth of vertically aligned high-quality zinc oxide (ZnO) nanorods by the sonochemical method. A total of four samples categorized into two groups were evaluated, with a different type and thickness of seed layer for the first group - ZnO, 85 nm and the second group - Zn, 55 nm respectively. This was after depositing Ti (10 nm) as the adhesion layer on p-type Si (111) substrates for two samples, and without the adhesion layer on the others. All depositions were carried out using RF-sputtering. The effects of the seed layers on the growth of vertically aligned high-quality ZnO nanorods were systematically studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). Results show that the type and thickness of a seed layer are key parameters to the synthesis of high quality ZnO nanorods. Results also show that the Ti (10 nm) adhesion layer did not affect the growth surface-to-volume ratio of the ZnO nanorods and the ZnO nanorods synthesized using ZnO (85 nm) as seed layer has a better surface-to-volume ratio compared to that using Zn (55 nm) as seed layer, with and without the adhesion layer.

2016 ◽  
Vol 675-676 ◽  
pp. 130-133
Author(s):  
Wissawat Sakulsaknimitr ◽  
Kanyakorn Teanchai ◽  
Mati Horprathum ◽  
Chanunthorn Chananonnawathorn ◽  
Saksorn Limwichean ◽  
...  

ZnO nanorods were grown on magnetron sputtered ultra-thin ZnO seed layers through a hydrothermal method. Before ZnO nanorods growth, the ultra-thin ZnO seed layer has been annealed at temperatures ranging from 100 to 400°C in air. The influence of annealing treatment on the crystalline structure of the ultra-thin ZnO seed layers has been investigated by X-ray diffraction (XRD). The size and density of final prepared ZnO nanorods were investigated by field-emission scanning electron microscopy (FE-SEM). It was found that the length and the aspect ratio of the ZnOnanorods can be readily tuned by control of the ZnO ultra-thin seeds layer which results from the annealing treatment process.


2019 ◽  
Vol 4 (1) ◽  
pp. 45-58
Author(s):  
S. Mageswari ◽  
Balan Palanivel

Background: Zinc oxide (ZnO) is one of the most attractive II-VI semiconductor oxide material, because of its direct wide band gap (3.37 eV) and large binding energy (60 meV). Zinc oxide (ZnO) is a promising semiconductor due to its optimised optical properties. Among semiconductor nanostructures, the vertically aligned one-dimensional ZnO nanorods are very important for nano device application. Methods: Vertically aligned ZnO nanorod arrays were grown on ZnO, aluminum doped ZnO (ZnO:Al), tantalum doped ZnO (ZnO:Ta) and aluminum and tantalum co-doped ZnO (ZnO:Al,Ta) seed layer by hydrothermal method. Results: The X-Ray Diffraction (XRD) investigation indicated the presence of hexagonal phase for the both seed layers and nanorods. The Scanning Electron Microscope (SEM) images of ZnO and doped ZnO seed layer thin-films show spherical shaped nanograins organized into wave like morphology. The optical absorption spectra revealed shift in absorption edge towards the shorter wavelength (blue shifted) for ZnO nanorods grown on ZnO:Al, ZnO:Ta and ZnO:Al,Ta seed layer compared to ZnO nanorods grown on ZnO seed layer. Conclusion: The increase in band gap value for the ZnO nanorods grown on doped ZnO seed layers due to the decrease in crystallite size and lattice constant as evidenced from XRD analysis. The unique property of Al, Ta doped ZnO can be used to fabricate nano-optoelectronic devices and photovoltaic devices, due to their improved optical properties.


2013 ◽  
Vol 802 ◽  
pp. 1-6
Author(s):  
Anumut Deachana ◽  
Paul K. Chu ◽  
Dheerawan Boonyawan

A simple synthesis route to high-quality ZnO nanorod is reported, utilizing ZnO thin films grown by Filtered Pulse Cathodic Vacuum Arc (FPCVA) deposition as seed layers and continuous growth by hydrothermal method. Depending upon the FPCVA deposited conditions, implanted voltages, thickness and annealing temperature of ZnO seed layer, the surface morphology of the ZnO nanorod on ZnO film was noticeably different. The average diameters of the nanorod on Al substrates varied from about 131.99 ± 23.87 to 418.17 ±75.50 nm. The grown ZnO nanorod showed a high crystallinity with energy gap of 3.37 eV and low defect density confirmed by UV/VIS Spectrometer and photoluminescence spectrum (PL). Large-area growth, quasi-aligned and high quality indicates that the ZnO nanorods produced have potential application in field emission and optoelectronic devices.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 702 ◽  
Author(s):  
Juan Matmin ◽  
Irwan Affendi ◽  
Salizatul Ibrahim ◽  
Salasiah Endud

Nanostructured hematite materials for advanced applications are conventionally prepared with the presence of additives, tainting its purity with remnants of copolymer surfactants, active chelating molecules, stabilizing agents, or co-precipitating salts. Thus, preparing nanostructured hematite via additive-free and green synthesis methods remains a huge hurdle. This study presents an environmentally friendly and facile synthesis of spherical nanostructured hematite (Sp-HNP) using rice starch-assisted synthesis. The physicochemical properties of the Sp-HNP were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DR UV-Vis), and nitrogen adsorption–desorption analysis. The Sp-HNP showed a well-crystallized structure of pure rhombohedral phase, having a spherical-shaped morphology from 24 to 48 nm, and a surface area of 20.04 m2/g. Moreover, the Sp-HNP exhibited enhanced photocatalytic degradation of methylene blue dye, owing to the large surface-to-volume ratio. The current work has provided a sustainable synthesis route to produce spherical nanostructured hematite without the use of any hazardous agents or toxic additives, in agreement with the principles of green chemistry for the degradation of dye contaminant.


2010 ◽  
Vol 663-665 ◽  
pp. 1163-1166
Author(s):  
Cun Ying Xu ◽  
Yi Xin Hua

A new and facile route has been developed to synthesize β-Ni(OH)2 nanostructures using ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) as reaction media under solvothermal conditions. The β-Ni(OH)2 with different morphologies, such as nanoflakes, nanoplatelet and nanorods, can be obtained by controlling the volume ratio of the ionic liquid to water and reaction temperature. The as-prepared products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).


2011 ◽  
Vol 364 ◽  
pp. 35-39 ◽  
Author(s):  
Salina Muhamad ◽  
Abu Bakar Suriani ◽  
Mohamad Hafiz Mamat ◽  
Rafidah Ahmad ◽  
Mohamad Rusop

Rectifying behavior more than 3 orders of aligned zinc oxide (ZnO) nanorods grown on Mg0.3Zn0.7O thin film template using chemical bath deposition method was observed, giving a barrier height of 0.75 eV, and the ideality factor achieved was almost 6, which was analyzed using thermionic emission theory. Field emission scanning electron microscope (FESEM) images revealed that the grown ZnO was in hexagonal shape, uniformly distributed and in vertically aligned form. The crystallinity of the sample being studied using X-ray diffraction (XRD), where the highest peak was found at (002) phase, confirming that high crytallinity of ZnO was attained. The effect of metal/semiconductor junction between metal and aligned ZnO nanorods was discussed in further details.


2020 ◽  
Vol 27 (08) ◽  
pp. 1950198
Author(s):  
ABDULQADER D. FAISAL ◽  
MOHAMMAD O. DAWOOD ◽  
HASSAN H. HUSSEIN ◽  
KHALEEL I. HASSOON

In this work, ZnO nanorods (ZnO NRs) were successfully synthesized on FTO-glass via hydrothermal technique. Two steps were followed to grow ZnO NRs. In the first step, the seed layer of ZnO nanocrystals was deposited by using a drop cast method. The second step was represented by the hydrothermal growth of ZnO NRs on a pre-coated FTO- glass with the seed layer. The hydrothermal growth was conducted at 90∘C for 2[Formula: see text]h. The resulted structure, morphology and optical properties of the produced layers were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and UV-visible spectrophotometer, respectively. The analysis confirmed that the ZnO NRs grown by the hydrothermal method have a hexagonal crystal structure which was grown randomly on the FTO surface. The crystallite size was recorded 50[Formula: see text]nm and a slight microstrain (0.142%) was calculated. The bandgap was found to be in the range of 3.14–3.17[Formula: see text]eV. The ZnO NRs have a high density and large aspect ratio. A pH sensor with high sensitivity was fabricated using a two-electrode cell configuration. The ZnO NRs sensor showed the sensitivity of [Formula: see text]59.03[Formula: see text]mV/pH, which is quite promising and close to the theoretical value ([Formula: see text]59.12[Formula: see text]mV/pH).


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Da Zhang ◽  
Yuanyi Wang ◽  
Liang Chen ◽  
Chengjing Xiao ◽  
Jing Feng ◽  
...  

A simple two-step method of growing ZnO nanorod arrays on the surface of BiOI nanosheets was developed under mild environment. The hierarchical structure of ZnO arrays@BiOI nanosheets was characterized by various measurements like X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray detector. The optical absorption of the ZnO arrays@BiOI nanosheets composite was investigated by UV-Vis diffuse reflectance spectra. The photocatalytic degradation of methanol orange under visible light shows that the obtained ZnO arrays@BiOI nanosheets heterostructures exhibit enhanced photocatalytic activity, contrasting to the sum of BiOI nanosheets and ZnO nanorods. The mechanism of the photocatalytic process was discussed. This method of growing ZnO nanorod arrays on other nanosheets also provides a potential method to fabricating other complex structures.


2011 ◽  
Vol 1303 ◽  
Author(s):  
Hosang Ahn ◽  
Seon-Bae Kim ◽  
Dong-Joo Kim

ABSTRACTControlled ZnO nanostructures were grown on a flexible substrate for the future development of smart sensing tags. Thermolysis-assisted chemical solution deposition was used to grow ZnO nanorods at 85°C from 0.01mol of Zinc nitrate hexahydrate and HMT (Hexamethyltetramine) solution. To promote and modulate the ZnO nanorods, R.F. sputtered ZnO seed layers were deposited on polyimide substrates at various film thicknesses in the range of 8 to 160 nm. The optimum processing conditions to fabricate ZnO nanostructures have been investigated to examine the growth behaviors and to correlate the process parameters with the morphological characteristics. When the ethanol gas sensitivities were measured at different thickness of ZnO seed layers before growing ZnO nanorods, the highest sensitivity was obtained at 40 nm thick ZnO film at 300°C where the film thickness is similar to the Debye length. When ZnO nanorods were grown on such a ZnO seed layer, the sensitivities were more heavily influenced by the ZnO nanostructures rather than the thickness of the seed layer probably due to the dominant proportion of carrier density involved with the gas absorption.


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