scholarly journals Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

2017 ◽  
Vol 17 ◽  
pp. 101-105 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
Durairaj Benny Anburaj ◽  
G. Nedunchezhian ◽  
R. Meenambika

Zinc oxide has been receiving an enormous attention due to its potential applications in a variety of field such as optoelectronics, spintronics and sensors. Ag and In co-doped ZnO nanoparticles with different doping concentration 0.1M, 0.2M and 0.3M were prepared by sol-gel method via microwave irradiation followed by calcinations at 600°C for 2h. The structure and morphology were examined by X-ray diffraction (XRD), and Scanning Electron Microscope (SEM), respectively. Elemental composition has been estimated by Energy Dispersive X-ray Absorption (EDAX), while chemical properties are studied by Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) . The average particle size of the synthesized ZnO nanoparticles was calculated using the Scherrer formula and is found to be of less than 20 nm. Also the effect on the structure and the morphological properties of ZnO when co-doped with silver and Indium is examined. As the process is simple and low cost, it has the potential to be produced on a large scale.


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.


2021 ◽  
Author(s):  
Syed Irtiqa ◽  
Atikur Rahman

Abstract In the present work, ZnO nanoparticles were doped with varying concentration of Lanthanum (La), Cerium (Ce) and Dysprosium (Dy) using a simple and cost effective co-precipitation approach at low temperatures. The resulting powders were calcined at 500 °C for 1 hour using a muffle furnace, to produce La, Ce, Dy co-doped ZnO nanoparticles with varying stoichiometry viz. Zn0.97La0.01Ce0.01Dy0.01O, Zn0.94La0.02Ce0.02Dy0.02O, Zn0.91La0.03Ce0.03Dy0.03O, Zn0.88La0.04Ce0.04 Dy0.04O and Zn0.85La0.05Ce0.05Dy0.05O. This is a simple approach for doping and doesn’t require and complex equipment, harmful chemical or sophisticated machinery. The synthesized powders were characterized using X-Ray diffraction (XRD) and Scanning electron microscopy (SEM) for studying the structure, purity, and grain morphology. The average particle size was calculated using XRD and was found to be 35 nm, it also indicated a hexagonal wurtizite structure with no secondary peaks. A change in morphology from nanorods to nanoflowers was observed as the concentration of dopants increased. Photoluminescence (PL) spectra indicated a red shift in the absorption edge towards the visible region of solar spectrum and this was further confirmed by Diffuse Reflectance Spectra (DRS). The photocatalytic properties of undoped and La, Ce, Dy co-doped ZnO nanoparticles were observed by examining the photodegradation of Rhodamine B dye under UV irradiation. Elimination of dye color indicated the total degradation of organic molecule. The results revealed that ZnO photocatalyst with La, Ce, Dy co-doping concentration Zn0.85La0.05Ce0.05Dy0.05O exhibited the best photocatalytic performance (95%) as compared to undoped ZnO. The improved photocatalytic performance can be attributed to the increased surface oxygen vacancies and adsorption capacity. Delay in recombination of charge carriers due to creation trap states in the bandgap of ZnO further improves the photocatalytic performance of doped samples.


KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 16
Author(s):  
Alfin Darari ◽  
Mukholit . ◽  
Arif Sony Wibowo

<p>Pollution is caused by dangerous heavy metal such as Pb, Cu and Zn are toxic in the body tissues of organisms such as fish in high concentrations, it will be harmful to human health The purpose is to create an eco-friendly fish preservative tool with cooling system of thermodynamics and photocatalytic Co doped ZnO nanoparticles. this device can reach temperature 15 oC. Then to reduce dangerous heavy metals and kill bacteria used principle of photocatalytic Co doped ZnO nanoparticles. Co doped ZnO synthesized by sol-gel method. Then proceeded to spray coating and drying with furnace. The result is a purple clear homogeneous solution. From the analysis of the obtained bandgap Co doped ZnO about 2.28 eV and from SEM generated that average particle size Co doped ZnO is 60 nm. From the result of Co doped ZnO can be initiated by visible light and may have antibacterial activity so that this material can be made as a tool to prevent the growth of microorganisms only using regular light </p><p><strong>Key words</strong> : Eco-friendly fish preservative tools; less energy based on cooling dynamic; Nano Co Doped ZnO. <br /><br /></p>


2007 ◽  
Vol 310 (2) ◽  
pp. e818-e820 ◽  
Author(s):  
Yen-Fa Liao ◽  
Tzu-Wen Huang ◽  
Ming-Zhe Lin ◽  
Kuan-Li Yu ◽  
Hua-Shu Hsu ◽  
...  

2021 ◽  
Vol 13 (9) ◽  
pp. 1732-1738
Author(s):  
Ahmad Umar ◽  
Ramesh Kumar ◽  
Rajesh Kumar ◽  
Ahmed A. Ibrahim ◽  
Mohsen A. M. Alhamami ◽  
...  

Co-doped ZnO nano-agglomerates were synthesized by a facile solution process. Several characterization techniques revealed the successful doping of the ZnO by Co ions. FESEM results showed the agglomeration of the Co-doped ZnO nanoparticles to form large-sized nano-agglomerates. The diameters of the spherical nanoparticles and the agglomerates were not found to be uniform. The diameters of the nano-agglomerates ranged from ~25 nm–120 nm. XRD spectrum confirmed the Wurtzite hexagonal phase of ZnO in Co-doped ZnO nanoagglomerates. The average particle size for Co-doped ZnO nano-agglomerates was 20.68 nm. The sensing parameters were examined by using Co-doped ZnO nano-agglomerates modified gold electrode through cyclic voltammetric and amperometric analysis. The sensitivity of 70.73 μAmM−1cm−2 and very low-detection limit of 0.2 μM was observed for H2O2. The corresponding linear dynamic concentration range was 0.2–1633 μM. The excellent sensing activities of the Co-doped ZnO nano-agglomerates for H2O2 were attributed to the improved intrinsic electric properties and increased inner defects density, particularly near the interface region.


2018 ◽  
Vol 24 (8) ◽  
pp. 5618-5623
Author(s):  
Lakkanna S Chougala ◽  
Mahantesh S Yatnatti ◽  
Ravi K Linganagoudar ◽  
Jagadish S Kadadevarmath

In this paper, we have reported the synthesis of zinc oxide (ZnO) nanoparticles by aqueous route method and its characterization. By X-ray diffraction pattern (XRD) study it reveals that ZnO has hexagonal wurtzite structure with average particle size of 16.5 nm. From the results of scanning electron microscope (SEM) and Atomic force microscope (AFM) images, particles were spherical in nature with good aggregation. Stoichiometric ratio of Zinc and oxygen were almost close which was revealed from energy dispersive analysis of X-ray (EDAX). From infrared spectroscopy (FTIR), peak of Zn–O bond appears at 433.43 cm−1. Direct band gap of ZnO was found to be 3.36 eV estimated from UV-Vis absorption spectra. The Photovoltaic properties of DSSC sensitized by Di-tetrabutylammonium cis-bis (isothiocyanato) bis (2,2′ -bipyridyl-4,4′-dicarboxylato) ruthenium(II) (N-719 dye) were obtained in which photo anode is prepared by synthesized ZnO. Photocurrent (I) and photovoltage (V) was measured using designed automated load variable solar simulator and optimum solar energy to electricity conversion efficiency (η) of 2.35% under AM 1.5 irradiation (1000 W/m2) was observed.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
N. B. Rithin Kumar ◽  
Vincent Crasta ◽  
B. M. Praveen

The current paper explores the preparation of PVA nanocomposites by doping with zinc oxide (ZnO) nanoparticles using the method of coagulation and solvent casting technique. The dopant zinc oxide nanoparticle is prepared by simple precipitation method and is confirmed by the X-ray diffraction (XRD) studies. The XRD studies explore that the average particle size of the synthesized nanoparticles is 55 nm and show that the crystallinity factor of PVA nanocomposites is influenced by the interaction occurring between the PVA main chain and the ZnO nanoparticle. The FTIR spectroscopy suggests that the formulation of complexes occurring between the dopants and the PVA main chain is due to inter or intra molecular hydrogen bonding. UV-vis spectra explore the dramatic decrease in the optical energy gap of nanoparticles doped polymer composites and the variations of Urbach energy (Eu) related to crystallinity for various dopant concentrations. The mechanical properties of the PVA nanocomposites were explored using universal testing machine (UTM) that reflects that, for x=15% doping concentration, there is an increase in the tensile strength, stiffness, and Young’s modulus, whereas, for x=7.5% concentration, the percentage total elongation at fracture is found to be the maximum. The morphological behavior and homogenous nanoparticle distribution in the composites were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX).


2019 ◽  
Vol 64 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Behnam Khanizadeh ◽  
Morteza Khosravi ◽  
Mohammad A. Behnajady ◽  
Ali Shamel ◽  
Behrouz Vahid

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples.


2013 ◽  
Vol 24 ◽  
pp. 123-132 ◽  
Author(s):  
S.M. Giripunje ◽  
Jyoti Ghushe

ZnO nanoparticles were prepared by chemical method using starch as capping agent. Also the polyaniline-zinc oxide (PANI-ZnO) nanocomposites were prepared by in-situ polymerization of aniline monomer with ZnO nanomaterials. The structure and morphology of the ZnO nanoparticles were investigated by X-ray diffraction and scanning electron microscopy. X-ray diffraction revealed the wurtzite structure of ZnO. Average particle size of the ZnO nanoparticles were also calculated from XRD. SEM micrographs showed the spherical shape of ZnO nanoparticles. Band gap energy of ZnO nanoparticles was determined from UV absorbance spectra and confirm quantum confinement. In UV-Vis spectra of PANI salt, two absorption peaks are observed at 320 and 630 nm. These absorption peaks arises due to excitation of the benzene segment including amine structures in polyaniline. A considerable large red shift at 360 nm from 320 nm has been observed for PANI-ZnO nanocomposites. This prominent red shift might occur due to the interaction between the hydroxyl groups of ZnO and the quinoid ring of emeraldine salt. Transport properties of PANI-ZnO nanocomposites were studied in terms of transport parameters such as DC electrical conductivity (σ), charge localization length (α-1), most probable hopping distance ® and hopping energy (w) using variable range hopping model as described by Ziller to conducting polymers.


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