Dependence of the electrical properties of Cu-doped ZnO nanoparticles decorated by Ag atoms

2020 ◽  
Vol 235 (6) ◽  
pp. 745-767
Author(s):  
Abueliz Modwi ◽  
Kamal K. Taha ◽  
Lotfi Khezami ◽  
Mohamed Boudina ◽  
Mohamed Khairy ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Great Influence ◽  
Impedance Measurement ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Nyquist Plots ◽  
Doped Zno

Abstract Silver decorated copper doped zinc oxide nanoparticles (Ag@Cu-ZnO) were successfully prepared via sol gel method. X-ray diffraction analysis revealed ZnO wurtzite crystalline structure with the existence of minor peaks attributed to Cu and Ag. The presence of Cu and Ag in addition to ZnO lattice was supplementary verified by EDS data while the shift in the FTIR band confirmed the Cu incorporation within the ZnO host lattice. Both SEM and XRD revealed an increase in particle size with Ag loading. At different frequencies, electrical measurements demonstrated a decrement in the dielectric constant, dielectric loss and AC conductivity with the increment of Ag content. Meanwhile, the Nyquist plots of the impedance measurement showed a single semicircle arc indicating the predominance of grain boundary resistance. This study elucidated the great influence of Ag on Cu-doped ZnO nanoparticles’ structural, dielectric constant and electrical conductivity which make it a promising candidate for catalytic, photocatalytic and adsorption applications.

Dependence of the electrical properties of Cu-doped ZnO nanoparticles decorated by Ag atoms

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Abueliz Modwi ◽  
Kamal K. Taha ◽  
Lotfi Khezami ◽  
Mohamed Boudina ◽  
Mohamed Khairy ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Great Influence ◽  
Impedance Measurement ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Nyquist Plots ◽  
Doped Zno

AbstractSilver decorated copper doped zinc oxide nanoparticles (Ag@Cu-ZnO) were successfully prepared via sol gel method. X-ray diffraction analysis revealed ZnO wurtzite crystalline structure with the existence of minor peaks attributed to Cu and Ag. The presence of Cu and Ag in addition to ZnO lattice was supplementary verified by EDS data while the shift in the FTIR band confirmed the Cu incorporation within the ZnO host lattice. Both SEM and XRD revealed an increase in particle size with Ag loading. At different frequencies, electrical measurements demonstrated a decrement in the dielectric constant, dielectric loss and AC conductivity with the increment of Ag content. Meanwhile, the Nyquist plots of the impedance measurement showed a single semicircle arc indicating the predominance of grain boundary resistance. This study elucidated the great influence of Ag on Cu-doped ZnO nanoparticles’ structural, dielectric constant and electrical conductivity which make it a promising candidate for catalytic, photocatalytic and adsorption applications.

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.

Synthesis and Structural Properties of (Co, Al) Co-Doped ZnO Nanoparticles

2018 ◽  
Vol 24 (8) ◽  
pp. 5636-5639
Author(s):  
P Swapna ◽  
S. Venkatramana Reddy
Keyword(s):  
Zno Nanoparticles ◽  
Lattice Site ◽  
Secondary Phase ◽  
Hexagonal Wurtzite Structure ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Local Vibration ◽  
Doped Zno ◽  
Co Doped ◽  
Prominent Peak

Pristine and (Co, Al) co-doped ZnO nanoparticles have been successfully synthesized by chemical coprecipitation method without using capping agent and annealed in the furnace at 500 °C for one hour. The aluminium concentration is fixed at 5 mol% and cobalt concentration is increasing from 1 to 3 mol%. X-ray diffraction results shows that all the samples possess hexagonal wurtzite structure of ZnO having no secondary phase after adding of aluminium and cobalt, which may be ascribed to the incorporation of cobalt an aluminium ions into the Zinc oxide host lattice site rather than interstitial. Non-uniform spherical nanoparticles were observed through SEM and the elemental analysis is determined through Energy dispersive spectroscopy (EDS). Raman spectrum shows that the prominent peak appeared at 530 cm−1, for co-doped samples which is attributed to the local vibration mode corresponds to cobalt bound with the donor defects.

Role of Sm3+ Doping on Structural, Optical and Photoluminescence Properties of ZnO Nanoparticles Synthesized by Sol-gel Auto- combustion Method

2020 ◽  
Vol 5 (3) ◽  
pp. 236-251
Author(s):  
Eshwara I. Naik ◽  
Halehatty S.B. Naik ◽  
Ranganaik Viswanath
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Combustion Method ◽  
Content Increase ◽  
Photoluminescence Properties ◽  
Tem Analysis ◽  
Auto Combustion ◽  
Ion Doping ◽  
Doped Zno ◽  
Pl Intensity

Background: Various interesting consequences are reported on structural, optical, and photoluminescence properties of Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles synthesized by sol-gel auto-combustion route. Objective: This study aimed to examine the effects of Sm3+-doping on structural and photoluminescence properties of ZnO nanoparticles. Methods: Zn1-xSmxO (x=0, 0.01, 0.03 and 0.05) nanoparticles were synthesized by sol-gel auto combustion method. Results: XRD patterns confirmed the Sm3+ ion substitution through the undisturbed wurtzite structure of ZnO. The crystallite size was decreased from 24.33 to 18.46 nm with Sm3+ doping. The hexagonal and spherical morphology of nanoparticles was confirmed by TEM analysis. UV-visible studies showed that Sm3+ ion doping improved the visible light absorption capacity of Sm3+ iondoped ZnO nanoparticles. PL spectra of Sm3+ ion-doped ZnO nanoparticles showed an orange-red emission peak corresponding to 4G5/2→6HJ (J=7/2, 9/2 and 11/2) transition of Sm3+ ion. Sm3+ ion-induced PL was proposed with a substantial increase in PL intensity with a blue shift in peak upon Sm3+ content increase. Conclusion: Absorption peaks associated with doped ZnO nanoparticles were moved to a longer wavelength side compared to ZnO, with bandgap declines when Sm3+ ions concentration was increased. PL studies concluded that ZnO emission properties could be tuned in the red region along with the existence of blue peaks upon Sm3+ ion doping, which also results in enhancing the PL intensity. These latest properties related to Sm3+ ion-doped nanoparticles prepared by a cost-efficient process appear to be interesting in the field of optoelectronic applications, which makes them a prominent candidate in the form of red light-emitting diodes.

The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films

2010 ◽  
Vol 97-101 ◽  
pp. 1611-1615 ◽  
Author(s):  
Qing Wang ◽  
Xin Li Li ◽  
Wei Nie ◽  
Yong Mei Xia ◽  
Jian Feng Dai
Keyword(s):  
Photocatalytic Activity ◽  
Absorption Spectra ◽  
Sol Gel ◽  
Composite Films ◽  
Wavelength Region ◽  
Tio2 Films ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Walled Carbon Nanotubes

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

Effect of cobalt doping on microstructures and dielectric properties of ZnO

2019 ◽  
Vol 97 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Ye Zhao ◽  
Fan Tong ◽  
Mao Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Co Doping ◽  
In Doping ◽  
Zno Powders ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Pure and cobalt-doped ZnO nanoparticles (2.5, 5, 7.5, and 10 atom % Co) are synthesized by sol–gel method. The as-synthesized nanoparticles are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) analysis. The nanoparticles of 0, 2.5, and 5 atom % Co-doped ZnO exhibited hexagonal wurtzite structure and have no other phases. Moreover, the (101) diffraction peaks position of Co-doped ZnO shift toward a smaller value of diffraction angle compared with pure ZnO powders. The results confirm that Co ions were well incorporated into ZnO crystal lattice. Simultaneously, Co doping also inhibited the growth of particles, and the crystallite size decreased from 43.11 nm to 36.63 nm with the increase in doping concentration from 0 to 10 atom %. The values of the optical band gap of all Co-doped ZnO nanoparticles gradually decreased from 3.09 eV to 2.66 eV with increasing Co content. Particular, the dielectric constant of all Co-doped ZnO ceramics gradually increased from 1.62 × 103 to 20.52 × 103, and the dielectric loss decreased from 2.36 to 1.28 when Co content increased from 0 to 10 atom %.

Sol–gel synthesis of Ba‐doped ZnO nanoparticles and its use in varistor ceramics

2018 ◽  
Vol 13 (10) ◽  
pp. 1506-1509 ◽  
Author(s):  
Rong Yang ◽  
Xiao Qu ◽  
Mao‐Hua Wang
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Doped Zno ◽  
Sol Gel Synthesis

scholarly journals SYNTHESIS OF ZnO-Аg NANOPARTICLES BY SOL-GEL METHOD

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Savka Janković ◽  
Dragana Milisavić ◽  
Tanja Okolić ◽  
Dijana Jelić
Keyword(s):  
Zno Nanoparticles ◽  
Wide Spectrum ◽  
Sol Gel ◽  
Synthesis Method ◽  
Material Surface ◽  
Characterization Methods ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Zinc oxide is a highly applicable semiconductor material. Wide applica-tion of this nanomaterial is connected to wide spectrum of energy band gap, high bond en-ergy, great thermal conductivity, but also with its non-toxicity, antibacterial activity, bio-compatibility and biodegradability characteristics. The aim of this paper is synthesis and characterization of silver doped ZnO nanoparticles (ZnO:Ag NP) using sol-gel method. Ob-tained samples of silver doped ZnO nanoparticles were characterized by following tech-niques: Fourier-transform infrared spectroscopy (FTIR), UV/VIS spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spec-troscopy (EDX). Efficiency of provided synthesis method was examined by FTIR spectros-copy. XRD determined the purity and crystallinity, and wurtzite structure of synthesized material. Surface morphology and the effect of doping were examined using SEM and EDX characterization methods. Results showed better conductivity after doping ZnO nanoparti-cles with silver. SEM micrographs showed ZnO:Ag NP in the form of nanorods with a par-ticle average size of 6 nm.

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