scholarly journals Enhanced Red Emission in Ultrasound-Assisted Sol-Gel Derived ZnO/PMMA Nanocomposite

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Van-Tuan Mai ◽  
Quang-Bac Hoang ◽  
Xuan-Dung Mai

Cost-effective methods for preparing ZnO nanostructures are of importance for the deployment of ZnO in many applications including n-type conduits, catalysts, nanophosphor, and optoelectronics. Herein, we present a room-temperature sol-gel method with the aid of ultrasonication to prepare white-emitting ZnO nanoparticles (NPs). X-ray diffraction and electron microscopic analyses revealed that the size and shape of ZnO NPs can be controlled simply by changing the concentration of the Zn precursor. The ZnO NPs had a broad photoluminescence emission, ranging from 450 nm to 800 nm, while their composite in PMMA matrix showed an enhancement in the red region induced by ZnO-PMMA interfacial band-bending effects. The results demonstrated herein promise a simple tool for control over size, shape, and emission of ZnO materials for diverse applications.

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.


2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.


Author(s):  
Selma M.H. AL-Jawad ◽  
Zahraa S. Shakir ◽  
Duha S. Ahmed

ZnO/MWCNTs hybrid and doped with different concentration of Nickel element prepared by using Sol-gel been technique reported. All samples were prepared and characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectroscopy have been identified the structural, optical and morphological properties. X-ray diffraction showed the polycrystalline nature with hexagonal wutzite structure of hybrid and doped with Nickel. The crystalline size of the hybrid nanostructure was increasing from 23.73 nm to 34.59 nm. Besides, the UV-Vis spectroscopy showed a significant decrease in the band gap values from 2.97 eV to 2.01 eV. Whereas the FE-SEM analysis confirm the formation spherical shapes of ZnO NPs deposited on cylindrical tubes representing the MWCNTs. The antibacterial activity reveals that the inhibition zone of Ni doped-ZnO/MWCNTs hybrid was 28.5 mm, 26.5 mm toward E. coli and S. aureus bacteria, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Thilagavathi Thirugnanam

Fibers irregular and seed-like microcrystalline ZnO were synthesized by using a cost-effective and low temperature aqueous sol-gel method. Various polymers, namely, polyethylene glycol 6000 (PEG 6000) and polyvinyl pyrrolidone (PVP), were used as structure directing agents. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The X-ray diffraction pattern revealed the formation of phase-pure ZnO micropowders. It is observed that the polymers play an important role in modifying the surface morphology and the size of the crystallites. A compact granular morphology is observed for the ZnO samples without polymer. The samples exhibit microparticles of size 100 nm for PVP and for PEG-mediated growth, whereas microporous corrugated morphology is observed for added PEG-mediated micropowder. FTIR study is used to confirm the structural modifications occurring in the polymers.


2012 ◽  
Vol 488-489 ◽  
pp. 666-670 ◽  
Author(s):  
M. Hussain Beevi ◽  
S. Vignesh ◽  
T. Pandiyarajan ◽  
P. Jegatheesan ◽  
R. Arthur James ◽  
...  

We report, synthesis and antifungal activities of CuO nanoparticles. Particles are prepared through sol-gel method. X-ray diffraction studies show the particles are monoclinic (crystalline) in nature. Scanning electron microscopic measurements are carried out to understand the morphology of the prepared particles. Energy-dispersive X-ray spectroscopic measurements show that the prepared particles containing Cu and O. To identify the local structure of the particles Fourier transform infra red (FTIR) spectroscopic measurements were carried out showing vibrational bands of Cu-O and O-H band. Anti fungal studies were performed on the set of fungal using disk diffusion method and found that the prepared particles are suitable for antifungal activities.


2016 ◽  
Vol 859 ◽  
pp. 18-23 ◽  
Author(s):  
Li Ping Zhao ◽  
Wen Hong Tao ◽  
Xing Hua Fu ◽  
Wen Zhe Cao ◽  
Guo Yuan Cheng ◽  
...  

(Ba0.5Sr0.5)1-xMnxTiO3(x=0,0.01,0.03,0.05)ceramics were prepared via a new sol-gel method with titannium oxide, strontium nitrate, barium nitrate and manganous nitrate as raw materials.The effect of Mn doping on the microstructure and dielectric properties of the BST were characterized by field scanning electron microscopy,x-ray diffraction and impedance analyser.It was found that the dopted ions could not alter the basic crystal strcuture and they only improved the material properties as modified ions when x≤0.3.The (Ba0.5Sr0.5)1-xMnxTiO3 ceramics sintered at 1250°C for 2h exhibited good dielectric properties(er=1330,tand=0.03)at room temperature and f=1KHz when x=0.03 and the grains were regular and uniform ,indicating a dense microstrcture.


2016 ◽  
Vol 5 (4) ◽  
pp. 196
Author(s):  
R. Palomino-Merino ◽  
R. Lozada-Morales ◽  
J. Martínez-Juárez ◽  
G. Juárez-Díaz ◽  
J. Carmona-Rodriguez ◽  
...  

Nanocrystalline Er-doped TiO2 was prepared by sol-gel at room temperature. X-ray diffraction, photoacoustic spectroscopy (optical absorption), transmission electron microscopy (TEM), and electron dispersion microscopy (EDS) were carried out on both as-prepared and thermally-annealed (air at 700 ºC) samples, revealing the anatase crystalline phase of TiO2. The samples exhibit an average grain size from 38 to 5.1 nm, as the nominal concentration of Er varies from 0 % to 7 %. The photoacoustic spectra evidence the absorption edge at 300 nm attributed to TiO2, as well as several electronic transitions which are atomic energy absorption-line levels characteristics of Er.


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.


2007 ◽  
Vol 546-549 ◽  
pp. 2097-2102
Author(s):  
Ting Luo ◽  
Yi Zhang ◽  
Qing Rong Feng

The relationship of the resistivity versus synthesizing temperature of sol-gel YBa2Cu3O7-x samples, with Tc 91K, was studied while synthesizing in flowing oxygen atmosphere. A set of high temperature -T curves were obtained for the whole process. After four rounds of synthesizing, the resistivity of the sample was =1.00×10-3cm at room temperature. The -T curve of the last round also showed that the orthorhombic to tetragonal phase transformation of the sample occurred around 600oC that is lower than the YBa2Cu3O7-x sample prepared in ambient atmosphere. Other measurements such as X-ray diffraction, SEM measurement, low temperature R-T and M-T measurement were also taken to get more information of these samples.


2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.


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