scholarly journals Green synthesis and characterization of zinc oxide nanoparticles using bush tea (Athrixia phylicoides DC) natural extract: assessment of the synthesis process.

F1000Research ◽  
2022 ◽  
Vol 10 ◽  
pp. 1077
Author(s):  
Gabriel Amani Kaningini ◽  
Shohreh Azizi ◽  
Hlengilizwe Nyoni ◽  
Fhatuwani Nixwel Mudau ◽  
Keletso Cecilia Mohale ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Spherical Shape ◽  
Average Crystallite Size ◽  
Synthesis Process ◽  
Nitrate Hexahydrate ◽  
Sem Images ◽  
Natural Extract ◽  
X Ray ◽  
Athrixia Phylicoides

Background: Nanoparticles are globally synthesized for their antimicrobial, anti-inflammatory, wound healing, catalytic, magnetic, optical, and electronic properties that have put them at the forefront of a wide variety of studies. Among them, zinc oxide (ZnO) has received much consideration due to its technological and medicinal applications. In this study, we report on the synthesis process of ZnO nanoparticles using Athrixia phylicoides DC natural extract as a reducing agent.   Methods: Liquid chromatography–mass spectrometry (LC-MS) was used to identify the compounds responsible for the synthesis of ZnO nanoparticles. Structural, morphological and optical properties of the synthesized nanoparticles have been characterized through X-ray diffraction (XRD), Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).   Results: LC-MS results showed that different flavonoids and polyphenols, as well as Coumarin, an aromatic compound, reacted with the precursor to form ZnO nanoparticles. XRD and UV-Vis analysis confirmed the synthesis of ZnO nanoparticles, with a spherical shape showed in SEM images. The quasi-spherical ZnO crystals had an average crystallite size of 24 nm. EDS and FTIR analysis confirmed that the powders were pure with no other phase or impurity.   Conclusions: This study successfully demonstrated that the natural plant extract of A. phylicoides DC. can be used in the bio-reduction of zinc nitrate hexahydrate to prepare pure ZnO nanoparticles, thus, extending the use of this plant to an industrial level.

scholarly journals Morphological, Structural, and Optical Bandgap Characterization of Extracted ZnO Nanoparticles from Commercial Paste

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Mahmoud Nabil ◽  
I. V. Perez-Quintana ◽  
M. Acosta ◽  
J. A. Mendez-Gamboa ◽  
R. Castro-Rodriguez
Keyword(s):  
Zno Nanoparticles ◽  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Xrd Analysis ◽  
Zno Nps ◽  
Sem Images ◽  
Visible Absorption ◽  
X Ray ◽  
Glass Substrates ◽  
Crystal Volume

ZnO nanoparticles (NPs) were extracted from a commercial paste in both colloidal and precipitate forms. The Zetasizer analysis performed on the colloid showed ZnO NPs ranging from ∼30 nm to ∼100 nm. Thin films of ZnO were deposited on glass substrates by spin-coating technique from a mixture of the extracted colloid and precipitate. The scanning electron microscope (SEM) images showed uniformly arranged, mesoporous, and nanostructured ZnO particles of different shapes, with an estimated film thickness of 0.67 μm. Analysis by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD) confirmed the presence of ZnO in the films, with no impurities or remnants of other materials. The XRD analysis showed a polycrystalline nature of the films and identified a pure phase formation of the hexagonal wurtzite structure. The average crystallite size calculated from the diffraction peaks is ∼43.25 nm. The calculated crystal tensile strain is 1.954 × 10−3, which increases the crystal volume by 0.728% compared with the crystal volume of standard ZnO. The calculated crystal parameters are a = b = 3.258 Å and c = 5.217 Å. The calculated dislocation density (d) and bond length Zn–O (L) are 5.35 × 10−4 nm−2 and 2.695 Å, respectively. Ultraviolet-visible absorption spectra showed an optical band gap of ∼3.80 eV.

scholarly journals Effects of Chromium Doping on the Electrical Properties of ZnO Nanoparticles

2020 ◽  
Vol 4 (2) ◽  
pp. 82-88 ◽  
Author(s):  
S. Janet Priscilla ◽  
V. Andria Judi ◽  
R. Daniel ◽  
K. Sivaji
Keyword(s):  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Electrochemical Impedance ◽  
Chemical Properties ◽  
Average Crystallite Size ◽  
Precipitation Method ◽  
Electromagnetic Spectrum ◽  
Nitrate Hexahydrate ◽  
Pure Zinc ◽  
Vis Spectroscopy

Nanostructured ZnO has gained a considerable amount of attention due to its unique physical and chemical properties and due to its remarkable performance in the fields of optics, photonics and electronics. The scope of this work is to study the Structural, Optical and Electronic properties of Pure Zinc Oxide (ZnO) and Chromium doped Zinc Oxide nanoparticles. These nanoparticles were synthesized by low-temperature precipitation method at various concentrations in the range (Zn1-xCrxO; (x = 0, 0.1& 0.3)). The precursors used were analytical grade Zinc Nitrate Hexahydrate and Chromium Nitrate Nona hydrate. The synthesized nanoparticles were annealed at 400°C. The Structural property of the synthesized nanoparticles was analysed by XRD (X-Ray diffraction) and was confirmed to exhibit a crystalline hexagonal wurtzite structure with an average crystallite size of 55nm. The functional groups were analysed using FTIR (Fourier Transformed Infra-red spectroscopy). The Morphology was analysed by FESEM (Field Emission Scanning Electron Microscope) and a change in morphology from spherical to spindle like structure was observed. The Optical properties were analysed using UV-Vis spectroscopy, the absorption spectrum for electromagnetic spectrum was observed and the changes in the optical band gap of ZnO nanoparticles with Chromium dopant addition were calculated to be in the range of 3.6 eV. The Electrical property of the synthesised nanoparticles was analysed using Electrochemical Impedance Spectroscopy (EIS) and the conductivity was calculated to be in the range of 1.1e-07S/m.

ZINC OXIDE NANOPARTICLES FOR ULTRAVIOLET PHOTODETECTION

2011 ◽  
Vol 20 (01) ◽  
pp. 183-194 ◽  
Author(s):  
SHAYLA SAWYER ◽  
LIQIAO QIN ◽  
CHRISTOPHER SHING
Keyword(s):  
Zinc Oxide ◽  
Gallium Nitride ◽  
Zno Nanoparticles ◽  
Green Emission ◽  
Synthesis Process ◽  
Voltage Response ◽  
Zno Nanoparticle ◽  
Linear Current ◽  
Current Voltage ◽  
Lift Off

Zinc Oxide ( ZnO ) nanoparticles were created by a top-down wet-chemistry synthesis process ( ZnO - A ) and then coated with polyvinyl-alcohol (PVA) ( ZnO - U ). In ZnO - U , strong UV emission was apparent while the parasitic green emission, which normally appears in ZnO suspensions, was suppressed. A standard lift-off process via e-beam lithography was used to fabricate a detector by evaporating Aluminum ( Al ) as ohmic electrodes on the ZnO nanoparticle film. Photoconductivity experiments showed that linear current-voltage response were achieved and the ZnO - U nanoparticles based detector had a ratio of UV photo-generated current more than 5 times better than that of the ZnO - A based detector. In addition, non-linear current-voltage responses were observed when interdigitated finger Gold ( Au ) contacts were deposited on ZnO - U . The UV generated current to dark current ratios were between 4 and 7 orders of magnitude, showing better performance than the photodetector with Al contacts. ZnO - U were also deposited on Gallium Nitride ( GaN ) and Aluminum Gallium Nitride ( AlGaN ) substrates to create spectrally selective photodetectors. The responsivity of detector based on AlGaN is twice that of commercial UV enhanced Silicon photodiodes. These results confirmed that ZnO nanoparticles coating with PVA is a good material for small-signal, visible blind, and wavelength selective UV detection.

Microwave Synthesis of ZnO Nanoparticles for Enhanced Oil Recovery

2014 ◽  
Vol 1024 ◽  
pp. 83-86 ◽  
Author(s):  
Mohamad Sahban Alnarabiji ◽  
Noorhana Yahya ◽  
Sharifa Bee Abd Hamid ◽  
Khairun Azizi Azizli ◽  
Afza Shafie ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zno Nps ◽  
Nanoparticle Morphology ◽  
Original Oil In Place

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).

scholarly journals Zinc oxide nanoparticles prepared by thermal decomposition of zinc benzenepolycarboxylato precursors: Photoluminescent, photocatalytic and antimicrobial properties

2020 ◽  
Vol 85 (11) ◽  
pp. 1475-1488
Author(s):  
Lidija Radovanovic ◽  
Jelena Zdravkovic ◽  
Bojana Simovic ◽  
Zeljko Radovanovic ◽  
Katarina Mihajlovski ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Antimicrobial Properties ◽  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Inhibitory Effect ◽  
Reactive Orange 16 ◽  
Air Atmosphere

Zinc oxide (ZnO) nanoparticles were obtained by thermal decomposition of one-dimensional zinc?benzenepolycarboxylato complexes as single- -source precursors at 450 ?C in an air atmosphere. The mechanism and kinetics of thermal degradation of zinc?benzenepolycarboxylato complexes were analyzed under non-isothermal conditions in an air atmosphere. The results of X-ray powder diffraction and field emission scanning electron microscopy revealed hexagonal wurtzite structure of ZnO with an average crystallite size in the range of 39?47 nm and similar morphology. The band gap and the specific surface area of ZnO nanoparticles were determined using UV?Vis diffuse reflectance spectroscopy and the Brunauer, Emmett and Teller method, respectively. The photoluminescent, photocatalytic and antimicrobial properties of the ZnO nanoparticles were also examined. The best photocatalytic activity in the degradation of C. I. Reactive Orange 16 dye was observed for the ZnO powder where the crystallites form the smallest agglomerates. All ZnO nanoparticles showed excellent inhibitory effect against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli.

scholarly journals Mechanochemical Synthesis of Fluorapatite-Zinc Oxide (FAp-ZnO) Composite Nanopowders

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Bahman Nasiri-Tabrizi ◽  
Abbas Fahami
Keyword(s):  
Zinc Oxide ◽  
Average Crystallite Size ◽  
Structural Features ◽  
Morphological Features ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Remarkable Change ◽  
X Ray ◽  
Process Characterization ◽  
Ft Ir

Fluorapatite-zinc oxide (FAp-ZnO) composite nanopowders were successfully prepared via mechanochemical process. Characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) analysis, energy dispersive X-ray spectroscopy (EDX), and field-emission scanning electron microscopy (FE-SEM) techniques. Results revealed that in the absence of ZnO which produced by hydrothermal method, the single-phase FAp had high-crystalline structure with appropriate morphological features. Furthermore, after 5 h of milling in the presence of 5 wt.% ZnO, FAp-5 wt.% ZnO, composite nanopowders with no impurity phase was obtained. Structural studies illustrated that the milling up to 5 h was not accompanied by a remarkable change in the structural features. Moreover, the gained composite powders presented an average crystallite size of about 40 nm for FAp. The FE-SEM observations indicated that the experimental outcome had a cluster-like structure which consisted of several small particles. Finally, results propose a new approach to prepare commercial amounts of novel FAp-based composite nanopowders with high quality and suitable structural and morphological features.

scholarly journals Influence of pretreatment on the properties of α-Fe2O3 and the effect on photocatalytic degradation of methylene blue under visible light

2020 ◽  
Vol 82 (11) ◽  
pp. 2415-2424
Author(s):  
S. Mokhtari ◽  
N. Dokhan ◽  
S. Omeiri ◽  
B. Berkane ◽  
M. Trari
Keyword(s):  
Methylene Blue ◽  
Average Crystallite Size ◽  
Sample Surface ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Lattice Constants ◽  
Electrochemical Pretreatment ◽  
Crystal Properties ◽  
Rhombohedral Symmetry

Abstract The hematite (α-Fe2O3) nanostructures were synthesized by thermal oxidation of metal at 500 °C under atmospheric pressure. We studied the effect of the electrochemical pretreatment of the substrate before calcinations and its impact on the morphology, crystalline structure, lattice microstructural, and optical properties of α-Fe2O3. Uniform nanosheets were observed on the sample surface after calcination; their dimension and morphology were accentuated by the pretreatment, as confirmed by the SEM images. The characteristics of the nanostructures, analyzed by X-ray diffraction (XRD), revealed a rhombohedral symmetry with the space group R-3c and lattice constants: a = 0.5034 nm and c = 1.375 nm. The average crystallite size and strain, determined from the Williamson-Hall (W-H) plot, showed substantial variations after the substrate pretreatment. The Raman spectroscopy confirmed the changes in the crystal properties of the hematite submitted to pretreatment. The diffuse reflectance allowed to evaluate the optical gap which lies between 1.2 and 1.97 eV, induced by the electrochemical processing. The photocatalytic activity of α-Fe2O3 films was assessed by the degradation of methylene blue (MB) under LED light; 15% enhancement of the degradation for the pretreated specimens was noticed.

Synthesis and Characterization of Silver Nanoparticles Anchored on Montmorillonite via Chemical Reduction

2016 ◽  
Vol 11 ◽  
pp. 30-37 ◽  
Author(s):  
Danica Louise S. Bonga ◽  
Ma. Manna Farrel B. Pinto ◽  
Mary Fatima T. Tayad
Keyword(s):  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Chemical Reduction ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Clay Particles ◽  
X Ray ◽  
Mean Size

Montmorillonite clay particles were decorated with silver (Ag) nanoparticles by chemical reduction of Ag nitrate with sodium citrate. X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) confirmed the presence of metallic Ag on the surface of montmorillonite. The average crystallite size of the Ag nanoparticles obtained from the broadening of the 111 Ag peak ranged at 13-16 nm. On the other hand, the apparent particle sizes obtained from the SEM images were about 79-128 nm, suggesting that the nanoparticles are polycrystalline and possibly agglomerated. The increase in the concentration of reducing agent produced smaller Ag nanoparticles with narrower size distribution. The antibacterial test showed that the Ag nanoparticles, with mean size of 79 nm, adsorbed on montmorillonite were able to inhibit the growth of Staphylococcus aureus (S. aureus) with an antimicrobial index of 0.4.

scholarly journals Antibacterial Activity of Ag-Doped TiO2 and Ag-Doped ZnO Nanoparticles

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gebretinsae Yeabyo Nigussie ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Berhanu Menasbo Tegegne ◽  
Yemane Araya Weldemichel ◽  
Tesfakiros Woldu Gebreab ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Zno Nanoparticles ◽  
Pathogenic Bacteria ◽  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Sem Images ◽  
X Ray ◽  
Doped Zno

We report in this paper antibacterial activity of Ag-doped TiO2 and Ag-doped ZnO nanoparticles (NPs) under visible light irradiation synthesized by using a sol-gel method. Structural, morphological, and basic optical properties of these samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum, and UV-Vis reflectance. Room temperature X-ray diffraction analysis revealed that Ag-doped TiO2 has both rutile and anatase phases, but TiO2 NPs only have the anatase phase. In both ZnO and Ag-doped ZnO NPs, the hexagonal wurtzite structure was observed. The morphologies of TiO2 and ZnO were influenced by doping with Ag, as shown from the SEM images. EDX confirms that the samples are composed of Zn, Ti, Ag, and O elements. UV-Vis reflectance results show decreased band gap energy of Ag-doped TiO2 and Ag-doped ZnO NPs in comparison to that of TiO2 and ZnO. Pathogenic bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, were used to assess the antibacterial activity of the synthesized materials. The reduction in the viability of all the three bacteria to zero using Ag-doped ZnO occurred at 60 μg/mL of culture, while Ag-doped TiO2 showed zero viability at 80 μg/mL. Doping of Ag on ZnO and TiO2 plays a vital role in the increased antibacterial activity performance.

Photocatalytic Activity of Sol-Gel Derived Bi2O3-TiO2 Nanocomposite

2012 ◽  
Vol 712 ◽  
pp. 73-83 ◽  
Author(s):  
C. Karunakaran ◽  
P. Magesan ◽  
P. Gomathisankar
Keyword(s):  
Visible Light ◽  
Deep Level ◽  
Anatase Phase ◽  
Sol Gel ◽  
Spherical Shape ◽  
Tween 80 ◽  
Electron Microscopic ◽  
Sem Images ◽  
X Ray ◽  
Crystallite Sizes

Bi2O3-TiO2 nanocomposites were obtained by sol-gel method using tween 80 (T-80) or polyvinyl pyrrolidone-polyethylene glycol (PVP-PEG) as templating agent. The powder X-ray diffraction (XRD) patterns of both the composites reveal the crystal structure of Bi2O3 as primitive tetragonal and TiO2 is in anatase phase. The energy dispersive X-ray (EDX) spectra provide the composition of Bi2O3 in Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG) as 3.8 and 20.4 mol. %, respectively. The average crystallite sizes of Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG), derived from XRD, are 9 and 17 nm, respectively. The scanning electron microscopic (SEM) images show the spherical shape of Bi2O3-TiO2 (T-80) and the composites are polycrystalline. The diffuse reflectance spectra (DRS) of the composites display faint absorption of visible light and strong absorption in UV-A region. The photoluminescence (PL) spectra of both the composites are similar and the observed near band gap emission (NBE) and deep level emission (DLE) agree with those of TiO2. The impedance spectra show that the charge-transfer resistances of the composites do not differ significantly. The visible light photoimpedance spectra display the photoconductance of Bi2O3-TiO2 (PVP-PEG) but not that of Bi2O3-TiO2 (T-80). Although the visible light-photocatalytic activities of the two nanocomposites to degrade dye do not differ significantly Bi2O3-TiO2 (T-80) under UV-A light degrades dyes faster than Bi2O3-TiO2 (PVP-PEG).

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