scholarly journals ZnO Nanoparticles on Si, Si/Au, and Si/Au/ZnO Substrates by Mist-Atomisation

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Z. Khusaimi ◽  
M. H. Mamat ◽  
N. Abdullah ◽  
M. Rusop

ZnO nanoparticles were prepared on Si substrates by a mist-atomisation technique. Precursor of aqueous solution zinc nitrate and HMTA were released on substrates heated at 200, 300, and400°Cconfined in chamber box. The surface of Si substrate was varied, that is, gold-seeded Si (Si/Au), ZnO nanorods on Si/Au (Si/Au/ZnO), and just Si. The samples were subsequently analysed by X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectroscopy to study their structural, surface morphology, and PL emission properties. Analysis from the XRD patterns of the films showed stronga-andc-axis lattice and of pure ZnO hexagonal wurtzite type. The crystallite size varied from 6 to 43 nm and was found to generally increase with increasing substrates' temperatures (Ts). SEM micrographs revealed granular-like structure throughout. Shifts pattern of PL emission at ultraviolet and visible range was found to support size changes observed. Both substrate surface type and deposition temperature were found to significantly affect crystalline growth of ZnO nanoparticles. Chemical equations and justification for growth patterns are also suggested.

2010 ◽  
Vol 97-101 ◽  
pp. 1550-1553 ◽  
Author(s):  
M.A. Bakar ◽  
Muhammad Azmi Abd Hamid ◽  
A. Jalar

Zinc oxide nanorods were grown on Si (100) and Platinum coated glass substrate by the aqueous chemical growth (ACG) in aqueous solution that contained zinc nitrate hexahydrate (Zn(NO3)2•6H20) and hexamethylenetetramine (C6H12N4). The obtained ZnO nanorods are uniformly distributed on the Platinum coated glass substrate surface from 1.5 h to 3 h growth time. Branched hexagonal rods were also found growth on these uniform nanorods. Branched hexagonal rods were found on Si (100) from 2 h to 3 h growth time. A small number of flower-like structures compared to the majority oval type structure suggest that secondary nucleation had occurred during the process of growth. All of the high intensity peaks, including the strong (101) peak, are assigned to wurtzite ZnO hexagonal indicating that the product is pure ZnO. The results found in this study revealed that the type substrate plays a role in determining the surface morphology of ZnO growth.


2012 ◽  
Vol 585 ◽  
pp. 154-158 ◽  
Author(s):  
Sulaxna Sharma ◽  
Devendra Naik ◽  
Vijaya Agarwala

Nanometric zinc oxide was prepared by sol-gel method using two different capping agents e.g., ethylene diamine (EDA) and citric acid (CAM) in different solvents. Nanorods of ZnO was prepared by sol-gel method using zinc nitrate hexahydrate (1M). The as-synthesized samples were characterized using XRD, FESEM-EDAX, TG/DTA techniques. FESEM micrographs suggest that the formation of nanorods of ZnO takes place for EDA and CAM in MeOH after calcination at 150 °C and 170 °C, respectively for 12h. The antibacterial activity tests (also known as plus-minus tests) were done by allowing bacteria to grow normally in laboratory conditions, and also by subjecting to ZnO nanoparticles in the powder form. On comparison of the above two Petri plates, the presence of a zone of inhibition indicates the antibacterial nature, which would have not existed if the bacteria did not experience any adverse effects by the presence of the ZnO nanorods. In the present study, the activity tested against Escherichia coli ATCC 25922 (gram-negative) Micrococcus leuteus and Bacillus subtilis (gram-positive) the results suggest the selective activity of the nanoparticles against these species.


2019 ◽  
Vol 74 (10) ◽  
pp. 937-944 ◽  
Author(s):  
Babiker Y. Abdulkhair ◽  
Mutaz E. Salih ◽  
Nuha Y. Elamin ◽  
A. MA. Fatima ◽  
A. Modwi

AbstractStrenuous efforts have been employed to prepare zinc oxide (ZnO) with eco-friendly methods; however, few studies have reported the fabrication of ZnO using a sustainable procedure. In this study, spherical ZnO nanoparticles were successfully fabricated for photocatalysis applications using a simple and eco-friendly method using an arabinose sugar solution. The ZnO nanoparticles with a wurtzite structure were obtained by combining zinc nitrate and arabinose in water, followed by heating, evaporation, and calcinations at different annealing temperatures. The annealed ZnO photocatalysts were characterised via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The findings revealed a hexagonal wurtzite structure and good crystallinity with crystallite size increasing from 18 to 31 nm by means of an increase in the annealing temperature. The photocatalytic performance was examined to determine the degradation of mix dye waste. The spherical ZnO nanoparticles showed mix pollutant degradation of 84 % in 25 min at 400 °C.


1995 ◽  
Vol 397 ◽  
Author(s):  
M. Barth ◽  
J. Knobloch ◽  
P. Hess

ABSTRACTThe growth of high quality amorphous hydrogenated semiconductor films was explored with different in situ spectroscopic methods. Nucleation of ArF laser-induced CVD of a-Ge:H on different substrates was investigated by real time ellipsometry, whereas the F2 laser (157nm) deposition of a-Si:H was monitored by FTIR transmission spectroscopy. The ellipsometric studies reveal a significant influence of the substrate surface on the nucleation stage, which in fact determines the electronic and mechanical properties of the bulk material. Coalescence of initial clusters occurs at a thickness of 16 Å for atomically smooth hydrogen-terminated c-Si substrates, whereas on native oxide covered c-Si substrates the bulk volume void fractions are not reached until 35 Å film thickness. For the first time we present a series of IR transmission spectra with monolayer resolution of the initial growth of a-Si:H. Hereby the film thickness was measured simultaneously using a quartz crystal microbalance with corresponding sensitivity. The results give evidence for cluster formation with a coalescence radius of about 20 Å. Difference spectra calculated for layers at different depths with definite thickness reveal that the hydrogen-rich interface layer stays at the substrate surface and does not move with the surface of the growing film. The decrease of the Urbach energy switching from native oxide to H-terminated substrates suggests a strong influence of the interface morphology on the bulk material quality.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
M. Kooti ◽  
A. Naghdi Sedeh

A new and simple method was applied for the synthesis of ZnO nanoparticles with an average size of 20 nm. In this microwave-assisted combustion method, glycine as a fuel and zinc nitrate as precursor were used. The final product was obtained very fast with high yield and purity. The synthesized nanoscale ZnO was characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FT-IR). The size and morphology of the ZnO nanoparticles have been determined by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. This is a simple and fast method for the preparation of ZnO nanoparticles with no need for expensive materials or complicated treatments.


2014 ◽  
Vol 67 (5) ◽  
pp. 819
Author(s):  
Syed Mujtaba Shah ◽  
Zafar Iqbal ◽  
Muzaffar Iqbal ◽  
Naila Shahzad ◽  
Amina Hana ◽  
...  

Porphyrin dyes have an inherent tendency to aggregate. This leads to a self-quenching phenomenon that hinders electron transfer to the conduction band of semiconductors in dye-sensitized solar cells. Self-quenching adversely affects the efficiency of solar cells. Here, we report the interaction of porphyrin with pristine and acid-functionalized fullerene molecules on the surface of ZnO nanoparticles under chemisorbed conditions. Chemisorption of porphyrin only on ZnO nanoparticles instigates aggregation of the porphyrin molecules. These aggregates can be effectively broken by chemisorbing fullerene molecules on the surface of the ZnO nanoparticles. This is due to self-assembly formation processes because of porphyrin–fullerene interactions. The nanohybrid material, consisting of ZnO nanorods, acid-functionalized porphyrin, and fullerene derivatives, was characterized by UV–visible spectroscopy, fourier transform infrared spectroscopy, fluorescence spectroscopy, and transmission electron microscopy. The material generates better performing dye-sensitized solar cells when compared with those fabricated from porphyrin-based photo-active material.


2016 ◽  
Vol 675-676 ◽  
pp. 69-72
Author(s):  
Krisana Chongsri ◽  
Wanichaya Mekprasart ◽  
Wisanu Pecharapa

In this work, we reported the preparation of F-doped ZnO nanoparticles by facile precipitation process using zinc nitrate and ammonium fluoride as starting precursors for Zn and F, respectively dissolved in deionized water. The precursor solution was prepared at various fluoride composition ranging from 1-5 wt%. The as-precipitated powders were calcined at different temperature from 500 °C to 700 °C for 2 h. Effect of calcination temperature and fluoride concentration on structural, morphologies, optical and electrical properties were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis spectroscopy, respectively. XRD results indicated the complete formation of hexagonal wurtzite structure of ZnO. SEM micrographs showed the agglomeration for each sample that noticeably influenced by fluoride content.


2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.


Author(s):  
Hanh

In this work, ZnO nanorods (NRs) were successfully grown on printed circuit board substrates (PCBs) by utilizing a one-step, seedless, low-cost hydrothermal method. It was shown that by implementing a galvanic cell structure in an aqueous solution of 80 mM of zinc nitrate hexahydrate and hexamethylenetetramine, ZnO NRs can directly grow on the PCBs substrate without the assistance of a seed layer. The effect of hydrothermal time on the surface morphologies, and the crystallinity of the as-grown ZnO nanorods (NRs) was also investigated. The as-grown ZnO NRs also exhibited a significant enhancement in vertical growth and their crystallinity with 5 hour growth.


2014 ◽  
Vol 1024 ◽  
pp. 83-86 ◽  
Author(s):  
Mohamad Sahban Alnarabiji ◽  
Noorhana Yahya ◽  
Sharifa Bee Abd Hamid ◽  
Khairun Azizi Azizli ◽  
Afza Shafie ◽  
...  

Synthesising zinc oxide nanoparticles to get certain specific characteristics to be applied in Enhanced oil recovery (EOR) is still challenging to date. In this work, zinc oxide (ZnO) nanoparticles were synthesised using the sol-gel method by dissolving zinc nitrate hexahydrate in nitric acid. The ZnO crystal and particles morphology and structure were determined using X-ray Diffractometer (XRD) and Field Emission Scanning Electron Microscope (FESEM). In this study, a microwave oven was used for annealing ZnO without insulating a sample in any casket. The results show that 30 and 40 minutes of annealing and stirring for 1 hour influenced the morphology and size of zinc oxide particles in nanoscale. These parameters could be tailored to generate a range of nanoparticle morphology (agglomerated nanoparticles in a corn-like morphology), a crystal size with the mean size of 70.5 and 74.9 nm and a main growth at the peak [10. EOR experiment were conducted by dispersing 0.10 wt% ZnO NPs in distilled water to form a ZnO nanofluid. Then the fluid was injected into the medium in the 3rd stage of the oil recovery to present EOR stage. It was found that ZnO nanofluid has the ability to extract 8% of the original oil in place (OOIP).


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