NANOSTRUCTURAL ZnO FABRICATED BY VAPOR-PHASE TRANSPORT IN AIR

2004 ◽  
Vol 18 (02) ◽  
pp. 225-232 ◽  
Author(s):  
C. X. XU ◽  
X. W. SUN ◽  
B. J. CHEN ◽  
C. Q. SUN ◽  
B. K. TAY
Keyword(s):  
Zinc Oxide ◽  
Growth Time ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Vapor Phase Transport ◽  
X Ray ◽  
Zno Nanostructure ◽  
Oxide Nanostructures ◽  
Vapor Liquid Solid Mechanism ◽  
Phase Transport

Nanostructural zinc oxide has been successfully fabricated by heating the mixture of ZnO and graphite powders in air. The growth of these zinc oxide nanostructures with respect to the growing time and temperature has been studied. The morphologies and the crystal structures have been characterized by scanning electronic microscopy and the X-ray diffraction. The results indicated that ZnO nanostructure formed mainly along the crystal orientation [002] on silicon substrate at moderate temperatures. The crystallization was improved by prolonging growth time and the morphologies mainly depended on the distribution of the growth temperature. The growth process was attributed to vapor-liquid-solid mechanism.

Synthesis and Spectral Analysis of PVP Capped Zinc Oxide Nanostructures

2015 ◽  
Vol 1086 ◽  
pp. 75-78
Author(s):  
R. Kiruba ◽  
Solomon Jeevaraj A. Kingson
Keyword(s):  
Zinc Oxide ◽  
Chemical Precipitation ◽  
Hexagonal Structure ◽  
Spectroscopic Techniques ◽  
Photoluminescence Spectra ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Prepared Nanostructures

Monodispersed polyvinylpyrrolidone capped nanostructures of zinc oxide are prepared through chemical precipitation technique. The prepared nanostructures are characterized by XRD, SEM and Photoluminescence spectroscopic techniques. X-ray diffraction studies confirm the hexagonal structure of zinc oxide nanostructures. Nanostructures of the prepared zinc oxide are confirmed by SEM. The emission wavelength of PVP capped zinc oxide is found to be 551 nm using photoluminescence spectra.

scholarly journals Bio-mediated synthesis of ZnO nanostructures from Thymus Schimperi leaves extract and its antibacterial and photocatalytic activities

2020 ◽  
Vol 9 (1) ◽  
pp. 808-813
Keyword(s):  
Zinc Oxide ◽  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Scanning Electron Micrographs ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Photocatalytic Activities ◽  
Scanning Electron

In this work, zinc oxide nanostructures were synthesized from thymus schimperi leaves extract and ZnSO4.7H2O precursor, and antibacterial and photocatalytic activities were studied. The as-synthesized nanostructures were characterized by UV-Vis spectrophotometer, powder X-ray diffraction, Fourier transform infrared spectrophotometer and scanning electron microscopy. Powder X-ray diffraction patterns revealed that the as-synthesized zinc oxide was hexagonal wurtzite structure with no peaks from other phases or impurity. The maximum UV-Vis spectrum peak at about 255 nm also supports the evidence for the formation of zinc oxide nanostructures. The presence of functional groups on the surface of the nanostructures from the Fourier transform infrared spectrum exhibited that the phytochemicals play a key role in the formation of the nanostructures. The appearance of peak at 595cm-1 in the spectrum further corroborates the presence of zinc oxide in the sample. Scanning electron micrographs depict that there was mesh like nanostructures on the surface, which are likely to be convenient for catalytic application. The synthesized nanostructures inhibited the growth of both gram-positive and gram-negative bacteria, showing its biocidal property. Moreover, Congo red, which is one of the carcinogenic textile dyes, has been photodegraded by 83.33% at a pH of 6.5 due to the as-synthesized zinc oxide nanostructures indicating its potential application for waste water treatment.

Zinc Oxide Nanostructures Synthesized by Thermal Oxidation of Zinc Powder on Si Substrate

2013 ◽  
Vol 328 ◽  
pp. 710-714 ◽  
Author(s):  
Suttinart Noothongkaew ◽  
Supakorn Pukird ◽  
Worasak Sukkabot ◽  
Bualoy Kasemporn ◽  
Prayoon Songsiririttikul ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Oxidation Process ◽  
Zinc Powder ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Average Width ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Different Temperatures ◽  
Higher Temperature

ZnO nanowhiskers were formed by a simple oxidation of metallic zinc powder 99.9% at different temperatures from 400-900 °C for 2 hours on the silicon substrate. The result can be obtained after the thermal oxidation process, the ZnO nanowhiskers with different morphologies at different temperatures in which these morphologies and composition of ZnO nanostructures were characterized by scanning electron microscope, (SEM) and X-ray diffraction, XRD. It was found that the products were nanowhiskers, the structure are triangular shapes with average width of 10-50 nm at the root, 10-30 nm at the tip and length in the range of 1-3 μm was observed by SEM. Temperature in the range of 600-700 °C was suitable for the preparation of ZnO nanowhiskers. At higher temperature of 800 °C, the concentrations of ZnO structures become lower and stronger. At the oxidized temperature of 900 °C, ZnO nanowhiskers were not found and surface morphology become to porous. These results indicate that the oxidation rate is faster than the diffusion rate of Zn vapor on the surface of ZnO nuclei.

Synthesis and crystal structure of a series of stoichiometric (n)-ITB molybdenum-bronze oxides containing trivalent arsenic

2019 ◽  
Vol 234 (9) ◽  
pp. 569-579
Author(s):  
Meriem Goudjil ◽  
Enrique Gutiérrez-Puebla ◽  
Paola Bonazzi ◽  
Eugenio Lunedei ◽  
Djillali Mezaoui ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Vapor Phase Transport ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Pyramidal Geometry ◽  
Vertex Sharing ◽  
Phase Transport

Abstract A series of six new single crystals of fully stoichiometric As3+-bearing Mo-oxides and partially W-substituted Mo-oxides with formula AsmO(Mo1−xWxO3)p (m = 1, 2; p = 5, 7, 9, 10 and 11 and 0 ≤ x ≤ 0.6) was successfully grown using vapor-phase transport in vacuo. The crystal structures were determined using single-crystal X-ray diffraction data. All these compounds exhibit acentric orthorhombic symmetry with Z = 2, and belong to the so-called (n)-ITB (intergrowth tungsten bronzes) family, with n = 2, 3, 4 and 5. The six (n)-ITB phases have the following formulae: (2)-AsMo5O16 (Pm 2a), (2)-As2Mo10O31 (Pma 2), (3)-AsMo7O22 (Pmn 21), (3)-As(Mo5.53W1.47)O22 (Pmn 21), (4)-As(Mo4.33W4.67)O28 (Pm 2a) and (5)-As(W6.63Mo4.37)O34 (Pmn 21). Their structures consist of vertex-sharing MO6 octahedral units (with M either Mo or Mo/W) connected so as to form three-dimensional frameworks. Such frameworks consist of perovskite tungsten bronzes (PTB) type slabs, from 2- to 5-octahedra wide, intergrown with single hexagonal tungsten bronzes (HTB) type slabs, stacked up to form pseudo-hexagonal tunnels along the a-axis. As3+ and additional oxygen atoms are located in off-center positions inside the tunnels, forming As–O bonds with peculiar arrangements. In particular, we obtained the first examples of structures where, besides the usual AsO3E distorted pyramidal geometry, As3+ adopts AsO4E coordination with a seesaw configuration.

Crystal Structural Studies of ZnO Nanorods and their Band Gaps

2014 ◽  
Vol 938 ◽  
pp. 71-75
Author(s):  
Muhd Firdaus Kasim ◽  
Norlida Kamarulzaman ◽  
Suraya Ahmad Kamil
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Zno Nanorods ◽  
Chelating Agent ◽  
Band Gaps ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
Oxide Nanostructures ◽  
Vis Spectroscopy

Zinc oxide nanostructures have been done by many scientists but amongst the soft chemistry methods, chelating agents are normally used. In this work zinc oxide nanostructures have been synthesized using a soft chemistry method without using a chelating agent. The precursor were annealed at various temperatures of 400 °C, 500 °C, 600 °C, 700 °C, 800 °C and 1200 °C for 24 h. Nanostructures are found with rod-like shapes and they are compared with larger oval morphology. X-Ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and UV-Vis spectroscopy were used for characterization. XRD results confirm that all peaks were pure and single phase without the presence of any impurities. It was found from electron microscopy results that the morphology of the materials annealed at 400 °C possesses nanorod shape and as the calcination temperature increases, the material consists of mixed rod, spherical and oval shapes. The aspect ratio of the materials decreases when the annealing temperature increases. The absorption edges of the materials annealed at higher temperatures show a red-shift implying that narrowing of the band gaps occur in the materials. Band gap were evaluated and found to be between 3.32 to 3.19 eV.

Surface Modification of Zinc Oxide Nanoparticles Using Polyethylene Glycol under Microwave Radiation

2015 ◽  
Vol 659 ◽  
pp. 609-614
Author(s):  
Pat Sooksaen ◽  
Anutra Keawpimol ◽  
Piyavan Deeniam ◽  
Panumart Boonkum
Keyword(s):  
Zinc Oxide ◽  
Polyethylene Glycol ◽  
Microwave Radiation ◽  
Chelating Agent ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
Zno Nanocrystals ◽  
Oxide Nanostructures ◽  
Average Size

This study investigated the effect of polyethylene glycol (PEG), with high molecular weight of 1500 and 4000, on the formation of zinc oxide nanostructures synthesized by microwave radiation. Microwave heating was carried out at 2.45 GHz at 480 and 640 watts with 5s/15s on/off step time. The precursors used were Zn(NO3)2.6H2O, NaOH and PEG. Microwave radiation generates heat to activate the formation of ZnO nanoparticles where the morphology can be controlled by the addition of PEG, time and heating power. The formation of wurtzite structure of ZnO was confirmed by X-ray diffraction. Morphology was investigated by a scanning electron microscope. PEG acted as a structure-directing agent or chelating agent resulting in the formation of rod-like and plate-like crystals. The average size of ZnO nanocrystals increased with increasing microwave power.

scholarly journals Manganese-Doped Zinc Oxide Nanostructures as Potential Scaffold for Photocatalytic and Fluorescence Sensing Applications

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 120
Author(s):  
Deepika Thakur ◽  
Anshu Sharma ◽  
Abhishek Awasthi ◽  
Dharmender Singh Rana ◽  
Dilbag Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Fluorescence Sensing ◽  
X Ray ◽  
Sensing Applications ◽  
Oxide Nanostructures ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Mn Doped

Herein, we report the photocatalytic and fluorescence sensing applications of manganese-doped zinc oxide nanostructures synthesized by a solution combustion technique, using zinc nitrate as an oxidizer and urea as a fuel. The synthesized Mn-doped ZnO nanostructures have been analyzed in terms of their surface morphology, phase composition, elemental analysis, and optical properties with the help of scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and UV-Visible (UV-Vis) spectroscopy. A careful observation of the SEM micrograph reveals that the synthesized material was porous and grown in very high density. Due to a well-defined porous structure, the Mn-doped ZnO nanostructures can be used for the detection of ciprofloxacin, which was found to exhibit a significantly low limit of detection (LOD) value i.e., 10.05 µM. The synthesized Mn-doped ZnO nanostructures have been further analyzed for interfering studies, which reveals that the synthesized sensor material possesses very good selectivity toward ciprofloxacin, as it detects selectively even in the presence of other molecules. The synthesized Mn-doped ZnO nanostructures have been further analyzed for the photodegradation of methyl orange (MO) dye. The experimental results reveal that Mn-doped ZnO behaves as an efficient photocatalyst. The 85% degradation of MO has been achieved in 75 min using 0.15 g of Mn-doped ZnO nanostructures. The observed results clearly confirmed that the synthesized Mn-dopedZnO nanostructures are a potential scaffold for the fabrication of sensitive and robust chemical sensors as well as an efficient photocatalyst.

scholarly journals Facile Synthesis of Silver-Doped Zinc Oxide Nanostructures as Efficient Scaffolds for Detection of p-Nitrophenol

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 108
Author(s):  
Deepika Thakur ◽  
Anshu Sharma ◽  
Dharmender Singh Rana ◽  
Nagesh Thakur ◽  
Dilbag Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Sharp Decrease ◽  
Diffraction Field ◽  
Zinc Oxide Nanostructures ◽  
Solution Combustion ◽  
Pure Zinc ◽  
X Ray ◽  
Oxide Nanostructures

In this paper, silver-doped zinc oxide nanoparticles were synthesized by using a solution combustion technique, in which zinc nitrate is used as an oxidizer and tartaric acid as a fuel. The phase composition, morphology and structural properties of the as-synthesized zinc oxide and silver-doped zinc oxide were established by using powdered X-ray diffraction, field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy studies. Due to well-defined morphologies and crystallinity, the pure zinc oxide and silver-doped zinc oxide nanostructures can be used as efficient chemical sensors for the detection of p-nitrophenol (PNP). ZnO was found to show a low value of the limit of detection (LOD), i.e., 2.175 µM/L, for p-nitrophenol sensing; moreover, a sharp decrease in the limit of detection was observed with an increase in the concentration of silver ions, and the LOD value decreased to 0.669 µM/L for 10 mol % silver-doped zinc oxide. It is therefore concluded that Ag-doped ZnO shows a lower limit of detection as compared to pure ZnO for p-nitrophenol sensing.

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