scholarly journals Structural and Optical Properties of Undoped and Er3+-Doped ZnO Nanoparticles Synthesized by Laser Ablation in Ethanol

Author(s):  
Nadir Fadhil Habubi ◽  
Raid A. Ismail ◽  
Esraa H. Hadi

In this paper ,we report on the fabrication and properties of undoped and 8.4% Er3+-doped ZnO nanoparticles synthesized by laser ablation in ethanol at laser fluence values2.92 J/cm2. The synthesized nanoparticles are characterized by structural properties using X-ray diffractrometer , scanning electron microscope and the optical properties are carried out through UV–Visible spectrophotometer. The X-ray diffractrometer pattern indicates that these nanoparticle were polycrystalline in nature with a hexagonal (wurtzite) phase. SEM reveals that The synthesized ZnO and Er-ZnO NPs have a spherical shape. Moreover, the optical band gaps calculated through UV spectroscopy are found to be decreased with doping from 3.3 to 3.2 eV.

2015 ◽  
Vol 50 (1) ◽  
pp. 21-28 ◽  
Author(s):  
F Hassan ◽  
MS Miran ◽  
HA Simol ◽  
MAB H Susan ◽  
MYA Mollah

ZnO nanoparticles (NPs) with size less than 100 nm were successfully prepared by a hybrid electrochemical-thermal method using metallic zinc and NaHCO3 without the use of any zinc salt, template or surfactant. The NPs were characterized by Fourier transform infra-red (FT-IR) spectroscopy, UV-visible spectroscopy, photoluminescence spectroscopy (PL), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. UV-visible spectral analysis indicated that the particle size increased with increasing calcination temperature. The band gap (3.91-3.83 eV) was higher for synthesized ZnO NPs than their bulk counterparts (3.37 eV). The FT-IR spectra at different calcination temperatures showed the characteristic band for ZnO at 450 cm-1 to be prominent with increasing temperature due to the conversion of precursor into ZnO. The wurtzite hexagonal phase was confirmed by XRD analyses for ZnO NPs calcined at 700oC. The green photoluminescent emission from ZnO NPs at different calcination temperatures is considered to be originated from the oxygen vacancy or interstitial related defects in ZnO. SEM images clearly showed that the NPs are granular and of almost uniform size when calcined at higher temperatures. EDX spectra further confirmed the elemental composition and purity of ZnO obtained on calcination at 700oC. The NPs are well dispersed near or above calcination temperature of 700oC.Bangladesh J. Sci. Ind. Res. 50(1), 21-28, 2015


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 821 ◽  
Author(s):  
H.S. Ali ◽  
Ali Alghamdi ◽  
G. Murtaza ◽  
H.S. Arif ◽  
Wasim Naeem ◽  
...  

In this work, microemulsion method has been followed to synthesize vanadium-doped Zn1−xVxO (with x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.10) nanoparticles. The prepared samples are characterized by several techniques to investigate the structural, morphology, electronic, functional bonding, and optical properties. X-ray diffractometer (XRD) analysis confirms the wurtzite phase of the undoped and V-doped ZnO nanoparticles. Variation in the lattice parameters ensures the incorporation of vanadium in the lattice of ZnO. Scanning electron microscopy (SEM) shows that by increasing contents of V ions, the average particle size increases gradually. X-ray Absorption Near Edge Spectroscopy (XANES) at the V L3,2 edge, oxygen K-edge, and Zn L3,2 edge reveals the presence and effect of vanadium contents in the Zn host lattice. Furthermore, the existence of chemical bonding and functional groups are also asserted by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). UV–Visible analysis shows that by increasing V+ contents, a reduction up to 2.92 eV in the energy band gap is observed, which is probably due to an increase in the free electron concentration and change in the lattice parameters.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gebretinsae Yeabyo Nigussie ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Berhanu Menasbo Tegegne ◽  
Yemane Araya Weldemichel ◽  
Tesfakiros Woldu Gebreab ◽  
...  

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.


2017 ◽  
Vol 14 (2) ◽  
pp. 146-152
Author(s):  
Neha Sharma ◽  
Sanjayay Kumar

In present study, undoped ZnO, Zn0.8Ag0.2O, Zn0.8Al0.2O and Zn0.6Al0.2Ag0.2O samples are synthesized by simple solution method. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX) and UV-visible (UV-Vis) spectroscopy are used to perform the characterization of undoped, doped and codoped samples. XRD analysis is exposed that hexagonal wurtzite crystalline structure obtained for undoped, doped and codoped samples without any extra representation of impurity phases. The crystalline size is when evaluated by using Scherrer, It has 44, 49, 41and 37nm for undoped ZnO, Zn0.8Ag0.2O, Zn0.8Al0.2O and Zn0.6Al0.2Ag0.2O samples. Similarly, the crystalline size and strain are also evaluated by Williamson hall (W-H) and size strain plot (SSP) for the undoped, doped and codoped nanoparticles. The evaluated crystalline size by SSP is three times greater than the result of the scherrer method. The SEM exposes that surface morphology of nanoparticle samples, in this case is the formation of large agglomeration in spherical shape with nanocrystallites of undoped and doped ZnO with apparent and definite boundaries. EDX points out the replacement of Al2+ and Ag+ with Zn2+ in ZnO matrix and consequences in the development of single-phase Zn1−x−yAgxAlyO. The blueshift is shown in UV-Vis absorption spectra because the band gap value increases with the increase in doping, except Ag+ doped ZnO nanoparticles.


2019 ◽  
Vol 30 (2) ◽  
pp. 46
Author(s):  
Ban Ali

Nanoparticles of semiconductor material have get more interest due to their desirable properties and applications in different areas. In this study Zinc Oxide Nanoparticles (ZnO NPs) were synthesized using laser ablation in water by applying (1600 pulses) of Nd- YAG laser ( λ = 1064 nm ) . The crystal structure morphology of synthesized ZnO NPs were investigated using X-Ray diffraction, atomic force microscope (AFM) , optical microscope image , and optical properties characterized using UV-VIS as well as FTIR spectroscopy . The investigation revealed high purity of the ZnO NPs thin film prepared with a regular and homogeneous semi-spherical shape nanoparticles distribution on the substrate surface with size around 50nm. The optical properties shows energy band gap (1.5 and 4) eV respectively. I-V characteristics have been studied for the heterojunction structure of (Ag/ZnO/Si/Al) indicates that this heterojunc-tion could be used as a solar cell with efficiency about 10.9%.


NANO ◽  
2021 ◽  
pp. 2150130
Author(s):  
Jyoti Sahu ◽  
P. A. Alvi ◽  
V. S. Vats ◽  
R. S. Meghwal ◽  
H. Sublania ◽  
...  

In this paper, structural, optical and electronic properties of ZnO nanoparticles were investigated with the variation in the annealing temperature. X-ray diffraction, High-Resolution Transmission Electron Spectroscopy, Absorption spectroscopy, Raman Spectroscopy and Soft X-ray spectroscopy techniques were invoked to investigate and gauge the effect of annealing temperature on these properties. Intact Hexagonal Wurtzite phase of the nanoparticles with increasing crystallinity and spherical shape with particle size between 20[Formula: see text]nm and 23[Formula: see text]nm [using both X-ray Diffractometer (XRD) and High-resolution Transmission of electron microscopy (HRTEM)], blue shift of absorption peak from 372[Formula: see text]nm to 366[Formula: see text]nm and Optical Band Gap from 3.24[Formula: see text]eV to 3.17[Formula: see text]eV (UV-Vis-NIR), narrowing of [Formula: see text] mode in Raman Spectra; all indicated enhanced crystallinity with increased annealing temperature. Effects produced by the sole variable such as annealing temperature on the indicative parameters in a definite order catapult the annealing conditions as a significant candidate for customized properties. To have a deeper insight at the electronic levels, Synchrotron-based X-ray absorption spectroscopic studies of ZnO nanoparticles were undertaken. The analysis of Soft XAS spectra showed the change in number of O 2[Formula: see text] and Zn 4[Formula: see text] unoccupied states with increasing particle size and crystallinity of ZnO nanoparticles for varying annealing temperature.


NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550021 ◽  
Author(s):  
Zhankui Cui ◽  
Senlin Li ◽  
Junqiang Zhou ◽  
Jianli Zhang ◽  
Suxiang Ge ◽  
...  

Spherical Bi 2 S 3 nanoparticles (NPs) were prepared by a facile in situ thermal sulfuration method. Different Bi 2 S 3 samples were obtained by controlling the sulfuration time. The products were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), Raman and Fourier-transform infrared (FT-IR) methods. The optical properties were examined by UV-visible-near-infrared (UV-Vis–NIR) and photoluminescence (PL) techniques. The results show that the phase of the products after sulfuration is pure and the spherical shape of Bi NPs has been successfully transmitted to Bi 2 S 3 samples. The light absorption edges exhibit red shift to 1060 nm while the light emission displays blue shift to 868 nm, compared with the energy bandgap of bulk Bi 2 S 3. The reason for the special optical properties of Bi 2 S 3 NPs by this in situ sulfuration route is considered to associate with the defects and quantum size effect of NPs.


2020 ◽  
Vol 1 (1) ◽  
pp. 38-41
Author(s):  
L.Umaralikhan ◽  
M. JAMAL MOHAMED JAFFAR

ZnO and Mg doped ZnO nanoparticles (NPs) were synthesized by green method using Psidium guajava leaf extract. X-ray power diffraction studies confirmed that, synthesized nanoparticles were retained the wurtzite hexagonal structure. In addition, the crystallite development in nanostructured ZnO and Mg doped ZnO NPs by X-ray peak broadening analysis. The individual contributions of small crystallite sizes and lattice strain to the peak broadening in pure and Mg doped ZnO NPs were studied using Williamson-Hall (W-H) analysis.


2016 ◽  
Vol 12 (12) ◽  
pp. 4593-4600
Author(s):  
A. Srithar ◽  
J.C. Kannan ◽  
T.S. Senthil

In the present investigation, MnxZn1-xO (x = 0.05, 0.075 and 0.1%) nanoparticles have been synthesized by simple precipitation method. Their structural, morphological and optical properties were examined by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Differential scanning calorimetry (DSC) and UV-Visible spectroscopy. The Powder X-ray diffraction studies confirmed that the manganese doped ZnO have a single phase nature with hexagonal wurtzite structure and Mn successfully incorporated into the lattice position of Zn in ZnO lattice. The FESEM and HRTEM images are coincided with each other for aggregation of particles in nature. The elemental analysis of doped samples has been evaluated by EDX. The antibacterial activity of Mn doped ZnO nanoparticles has also been examined.


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