Morphological and Luminescent Characteristics of ZnO Nanopowders Doped with Europium

2008 ◽  
Vol 591-593 ◽  
pp. 745-749 ◽  
Author(s):  
T.S. Barros ◽  
Bráulio Silva Barros ◽  
S. Alves ◽  
Ruth Herta Goldsmith Aliaga Kiminami ◽  
Hélio Lucena Lira ◽  
...  
Keyword(s):  
Fine Particles ◽  
Synthesis Method ◽  
Secondary Phase ◽  
Vitreous Silica ◽  
Zinc Nitrate ◽  
Luminescence Characteristic ◽  
Structure Morphology ◽  
Zno Powders ◽  
Red Luminescence ◽  
Luminescence Characteristics

Zinc oxide was obtained by combustion reaction synthesis method using microwaves energy to provide ignition to the mixture of zinc nitrate, europium and urea. The influence of the europium concentration on the structure, morphology and luminescence characteristics of the ZnO powders was investigated. The proportion of each reagent and fuel was calculated based on the propellants chemistry concepts. The solutions were mixed in a vitreous silica basin and submitted of external heating in a microwaves oven until self-ignition occurred. The resulting powders were characterized by X-ray diffractometer (XRD), granulometric distribution, scanning electronic microscopy (SEM) and emission spectroscopy. The XRD results showed the formation of ZnO:Eu3+ as main phase and Eu2O3 as secondary phase. The powder presented morphology constituted of fine particles agglomerates (<100nm) and red luminescence characteristic from Eu3+ ion.

scholarly journals Microwave-Assisted Combustion Synthesis of Nanocrystalline ZnO Powders Using Zinc Nitrate and Various Amount of Organic Fuels as Reactants: Influence of Reactant Parameters - A Status Review

Nano Hybrids ◽  
2014 ◽  
Vol 6 ◽  
pp. 75-110
Author(s):  
L.C. Nehru ◽  
C. Sanjeeviraja
Keyword(s):  
Combustion Synthesis ◽  
Flame Temperature ◽  
Synthesis Method ◽  
Zinc Nitrate ◽  
Adiabatic Flame Temperature ◽  
Molar Ratios ◽  
Microwave Assisted ◽  
Organic Fuels ◽  
Zno Powders ◽  
Xrd Techniques

Nanocrystalline ZnO powders have been synthesized by a novel and simple microwave-assisted combustion synthesis method using urea, glycine, carbohydrazine and citric acid as fuels and zinc nitrate as oxidant. The starting materials were directly mixed and a slurry precursor with high homogeneity was formed due to the hygroscopicity of the reactants. The precursor could be ignited at room temperature, resulting in dry, loose and voluminous ZnO powders. An interpretation based on an adiabatic flame temperature, amount of gases produced during reaction for various fuel-to-oxidizer molar ratios (ψ), has been proposed for the nature of combustion and its correlation with the characteristics of as-synthesized product. The variation of adiabatic flame temperature (Tad) with the ψ value was calculated theoretically according to the thermodynamic concept. The reaction process of the precursor was investigated by XRD techniques.

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Direct Thermal Decomposition Route Using Zinc Nitrate Hexahydrate

2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana
Keyword(s):  
Thermal Decomposition ◽  
Crystallization Temperature ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Absorption Peak ◽  
Synthesis And Characterization ◽  
Nitrate Hexahydrate ◽  
Different Temperatures ◽  
Zno Powders

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

Synthesis of ZnO Nanoparticles via Simple Wet-Chemical Routes

2013 ◽  
Vol 699 ◽  
pp. 133-137 ◽  
Author(s):  
Byeong Woo Lee ◽  
Jin Heui Koo ◽  
Tae Suk Lee ◽  
Yun Hae Kim ◽  
Jae Suk Hwang
Keyword(s):  
Single Phase ◽  
Hydrothermal Process ◽  
Processing Parameters ◽  
Zinc Nitrate ◽  
Precursor Concentration ◽  
Precipitation Process ◽  
Process Conditions ◽  
Crystallite Sizes ◽  
Zno Powders ◽  
Wet Chemical

Zinc oxide (ZnO) powders were synthesized by a simple precipitation and a hydrothermal process at the temperature range RT-100°C. In precipitation process, the powders were formed by mixing aqueous solutions of zinc nitrate with NaOH aqueous solution under controlled process conditions such as precursor concentration, reaction pH and temperature. Single phase ZnO particles can be easily synthesized in lower precursor concentration, higher reaction pH and temperature. The powders synthesized at room temperature exhibited plates, rods or pointed multipod morphologies depending on the concentration and pH. ZnO crystallites synthesized by hydrothermal process consisted mostly of well developed large or elongated crystallites of plates or rods in shape. The results reveal that the ZnO crystallite sizes and shapes would be efficiently controllable by changing the processing parameters of the preparation processes.

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Novel Combustion Synthesis Method

2010 ◽  
Vol 152-153 ◽  
pp. 674-678 ◽  
Author(s):  
Bing Wang ◽  
Li Dan Tang ◽  
Jian Zhong Wang
Keyword(s):  
Crystal Structure ◽  
Combustion Synthesis ◽  
Synthesis Method ◽  
Synthesis And Characterization ◽  
Particle Sizes ◽  
Hexagonal Crystal Structure ◽  
Hexagonal Crystal ◽  
Zno Powders ◽  
Scherrer Formula

Nanocrystalline ZnO powders have been synthesized by a novel combustion synthesis method using glycine and urea as mixed fuels and zinc nitrates as oxidant. The as-synthesized ZnO powders are characterized by DSC, XRD and SEM. Results show that the as-synthesized ZnO powders show well crystalline with hexagonal crystal structure and purity without any other impurities and the particle sizes are about 50~70nm calculated by the Scherrer formula.

Structural, Magnetic, and Ferroelectric Properties in Ion-Doped BiFeO3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 391-395
Author(s):  
Shu Xia Zhang ◽  
Yan Wei Ma
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Structural Phase ◽  
Magnetic Hysteresis ◽  
Synthesis Method ◽  
Secondary Phase ◽  
Rare Earth Ion ◽  
La Doping ◽  
Auto Combustion ◽  
La Doped

Rare-earth ion La is doped at the bismuth site in BiFeO3 to produce Bi0.8La0.2FeO3 polycrystalline ceramics via a sol-gel auto-combustion synthesis method. For comparison, the similar experiments are also carried out for the non-doped BiFeO3 at the same time. It is found that both non-doped and La doped BiFeO3 are composed of nanoscale crystallites (~50 nm). Furthermore, La doping suppresses the formation of the secondary phase and leads to a structural phase transition from a rhombohedral to an orthorhombic or a pseudotetragonal structure. More importantly, the magnetic and ferroelectric properties in La doped ceramics were both enhanced, as evidenced by the typical electric and magnetic hysteresis loops. These property evolutions can be attributed to the elimination of the secondary phase and the structural distortion caused by La doping.

Effect of fuel content on luminescence and antibacterial properties of zinc oxide nanocrystalline powders synthesized by the combustion method

RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 97770-97782 ◽  
Author(s):  
Trilok K. Pathak ◽  
Ashwini Kumar ◽  
C. W. Swart ◽  
H. C. Swart ◽  
R. E. Kroon
Keyword(s):  
Zinc Oxide ◽  
Citric Acid ◽  
Antibacterial Properties ◽  
Combustion Method ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Nanocrystalline Powders ◽  
Nitrate Hexahydrate ◽  
Citric Acid Monohydrate ◽  
Zno Powders

Nanoscale ZnO powders were synthesized via the combustion method using zinc nitrate hexahydrate as the source (oxidant) material and urea, and glycine or citric acid monohydrate as fuels.

scholarly journals Facile growth of high transmittance ZnO micro-rod clusters on indium tin oxide by a wet-chemical synthesis method

2021 ◽  
Vol 30 ◽  
pp. 263498332110389
Author(s):  
S Morkoç Karadeniz
Keyword(s):  
Chemical Synthesis ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Hexagonal Phase ◽  
Synthesis Method ◽  
Zinc Nitrate ◽  
Synthesis Process ◽  
Nitrate Hexahydrate ◽  
Wet Chemical Synthesis ◽  
Wet Chemical

A simple wet-chemical synthesis method was developed to fabricate Zinc oxide micro-rod clusters. The synthesis process involved the rapid dilution of a zinc-bearing alkaline solution at 150°C in a convection oven on indium tin oxide (ITO) substrates. The synthesis was carried out by immersing an unseeded ITO substrate in a mixture of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and hexamethylenetetramine ((CH2)6N4) aqueous solution. The obtained sample was annealed at 400°C for 2 h. The structural, morphological and optical properties of the synthesized ZnO microstructures were investigated by X-ray diffraction, scanning electron microscopy and ultraviolet-visible spectroscopy, respectively. The ZnO rod clusters are hexagonal phase of the wurtzite structure. The crystal grain sizes of the films were found to be 72.6, 84.3 and 66.3 nm for the (100), (002) and (101) crystal planes, respectively. The optical bandgap of the ZnO was determined to be 3.147 eV.

scholarly journals Zinc Oxide Synthesis from Extreme Ratios of Zinc Acetate and Zinc Nitrate: Synergistic Morphology

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 570
Author(s):  
Sujittra Kaenphakdee ◽  
Pimpaka Putthithanas ◽  
Supan Yodyingyong ◽  
Jeerapond Leelawattanachai ◽  
Wannapong Triampo ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Zinc Acetate ◽  
Near Infrared ◽  
Synergistic Effects ◽  
Zinc Nitrate ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Oxide Powders ◽  
Zno Powders

The synthesis of ZnO comprising different ratios of zinc acetate (ZA) and zinc nitrate (ZN) from the respective zinc precursor solutions was successfully completed via a simple precipitation method. Zinc oxide powders with different mole ratios of ZA/ZN were produced—80/1, 40/1, and 20/1. The crystallinity, microstructure, and optical properties of all produced ZnO powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis-NIR spectrophotometry. The average agglomerated particle sizes of ZnO-80/1, ZnO-40/1, and ZnO-20/1 were measured at 655, 640, and 620 nm, respectively, using dynamic light scattering (DLS). The optical properties of ZnO were significantly affected by the extreme ratio differences in the zinc precursors. ZnO-80/1 was found to have a unique coral-sheet structure morphology, which resulted in its superior ability to reflect near-infrared (NIR) radiation compared to ZnO-40/1 and ZnO-20/1. The NIR-shielding performances of ZnO were assessed using a thermal insulation test, where coating with ZnO-80/1 could lower the inner temperature by 5.2 °C compared with the neat glass substrate. Due to the synergistic effects on morphology, ZnO-80/1 exhibited the property of enhanced NIR shielding in curtailing the internal building temperature, which allows for its utilization as an NIR-reflective pigment coating in the construction of building envelopes.

Synthesis and Characterization of Hydrated Calcium Phosphate: Precursors for Obtaining Biocements

2014 ◽  
Vol 798-799 ◽  
pp. 443-448
Author(s):  
Priscila Ferraz Franczak ◽  
Nelson Heriberto Almeida Camargo ◽  
Pricyla Corrêa ◽  
Enori Gemelli
Keyword(s):  
Calcium Phosphate ◽  
Biomedical Applications ◽  
Fine Particles ◽  
Calcium Phosphates ◽  
Synthesis Method ◽  
Synthesis Process ◽  
Promising Alternative ◽  
Hydrated Calcium ◽  
Reactive Method

Calcium phosphates biocements are biomaterials that present crystallographic and mineralogical characteristics similar to human skeletal structure. This has led to the development of new calcium phosphates biomaterials for biomedical applications, especially biomaterials for repairing defects and bone reconstruction. Calcium phosphates biocements are a promising alternative in biomedical applications, for they are easy to mold, they have good wettability, hydration and hardening capacity during its application in biological means. This work aimed at the synthesis of hydrated calcium phosphates powder, through a simple reactive method, which will be the basis for the production of calcium phosphate biocimentos with self-setting reaction. Three calcium phosphates compositions were produced via CaCO3/phosphoric acid reactive method in the ratios Ca/P = 1,5; 1,6 e 1,67 molar. The presented results are associated to hydrated powder morphology and synthesis process control. Scanning Electron Microscopy (SEM) helped with the morphological characterization of the powders, the laser analysis method was used for determining particle size and the Fourier Transformed Infrared Spectroscopy (FTIR) gave support to the identification of H2O e PO43-grouping vibrational bands. The work showed that for the different powder compositions the hydrated calcium phosphate phase is formed by clustered fine particles. This demonstrated that the chosen synthesis method permits the obtention of hydrated calcium phosphates, precursors for later biocement production.

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