scholarly journals Luminescence Studies of Transition Metal (Cu+ and Ag+ Ions) Activated Alkali Zinc Mixed Phosphate

2021 ◽  
Vol 04 (05) ◽  
Author(s):  
Milind Jog ◽  
Keyword(s):  
Solid State ◽  
Transition Metal ◽  
Low Cost ◽  
Solid State Lighting ◽  
Precipitation Method ◽  
Prepared Phosphor ◽  
X Ray Diffraction ◽  
Chromaticity Coordinate ◽  
Co Precipitation ◽  
Cie Chromaticity

Because of the importance of inorganic phosphates in the solid-state lighting industry, KZnPO4 doped with some transition metal dopant ions like Cu+ and Ag+ ions were prepared by low-cost co-precipitation method at room temperature followed by annealing at a high temperature around 6500C. The prepared phosphors were characterized by X-ray diffraction. In the case of a Photoluminescence study for KZnPO4 doped with Cu+, the emission was observed at 425 nm, which corresponds to the emission of Cu+ ion. In the case of Ag+ doped KZnPO4, weak emission was observed at 420 nm, which is assigned to the emission of Ag+ ions. CIE chromaticity coordinate of KZnPO4 doped with Cu+ and Ag+ ions phosphor was also evaluated via using OSRAM SYLVANIA color calculator and colour purity of concentration was nearly 95% of Cu+ and Ag+ ions. The obtained outcomes revealed that the prepared phosphor shows potential application in the field of solid-state lighting.

Photocatalytic Activity of Zeolite Supported Transition Metal-(Co2+ and Cr2+) Doped ZnO: Comparative Study

2015 ◽  
Vol 827 ◽  
pp. 43-48
Author(s):  
Annisa Noorhidayati ◽  
Mia Putri Rahmawati ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Transition Metal ◽  
Zno Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Transition Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation

Transition metal ions (Co and Cr) doped ZnO nanoparticles supported on natural zeolite were synthesized using co-precipitation method. The synthesized samples were characterized by means of X-ray diffraction, energy dispersive X-ray, Fourier-transform infrared absorption, and UV-visible diffuse reflectance spectroscopy. The samples were further used as photocatalyst for degradation of methyl orange and methylene blue in aqueous solutions under UV light irradiation. The results showed that zeolite supported Cr-doped ZnO nanoparticles is more efficient compared with zeolite supported Co-doped ZnO nanoparticles. It is also revealed that zeolite supported samples possessed higher photocatalytic efficiency compared to bare samples.

scholarly journals Synthesis of ZnSe Nanocrystals for Solid-state Lighting Applications

2020 ◽  
Vol 31 (1) ◽  
Author(s):  
Tran Thi Kim Chi ◽  
Bui Thi Thu Hien ◽  
Hoang Nhu Thanh ◽  
Trinh Duc Thien ◽  
Pham Nguyen Hai
Keyword(s):  
Solid State ◽  
Large Scale ◽  
Low Cost ◽  
Solid State Lighting ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
Current Voltage ◽  
Precursor Ratio ◽  
Microscopy Characterization ◽  
Znse Nanocrystals

We report the large-scale synthesis of highly luminescent ZnSe nanocrystals (NCs) by a simple and low-cost hydrothermal method. XRD (X-ray Diffraction) and HR-TEM (High Resolution Transmission Microscopy) characterization studies confirmed the formation of as-synthesized ZnSe NCs in cubic structure. The optical property of ZnSe NCs were tunable via controlling the Zn:Se molar precursor ratio (0.5:1–1.5:1), reaction temperature (150–200 0C), and reaction time (5–30 h). The resulting ZnSe NCs with the Zn:Se precursor ratio of 1:1, hydrothermally treated at 190 0C for 20 h exhibited the highest photoluminescence quantum yield obtained by PL spectra with the 355 nm excitation. The current–voltage (I–V) characteristics of the ZnSe NCs show its promising application in the solid-state lighting.

Investigation on Synthesis and Property of Tb3+/Dy3+ Co-Doped Gd3Al5O12 Phosphor

2017 ◽  
Vol 726 ◽  
pp. 261-265 ◽  
Author(s):  
Xin Teng ◽  
Bin Li ◽  
Jin Kai Li ◽  
Guang Bin Duan ◽  
Zong Ming Liu
Keyword(s):  
Green Emission ◽  
Color Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Efficient Energy Transfer ◽  
Green Phosphor ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Cie Chromaticity

The (Gd0.9-xTb0.1Dyx)3Al5O12 (x=0-0.04, GdAG:Tb3+/Dy3+) solid solution was acquired by calcining their respective precursor prepared via co-precipitation method at 1500 °C. The performance of GdAG:Tb3+/Dy3+ powders was characterized by combined technology of Fourier transform infrared absorption spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and photoluminescence (PL) spectrum analyses. The metastable Gd3Al5O12 could be stabilized by doping smaller Tb3+ ions of 10 at.%. Under the optimal UV excitation of 275 nm, the GdAG:Tb3+/Dy3+ phosphors exhibit vivid green emission at 548 nm which were attributed to the 5D4→7F5 transition of Tb3+. The CIE chromaticity coordinate was determined at (~0.32, ~0.48) with the color temperature of ~5872 K. Compared to the Dy3+-free (Gd0.9Tb0.1)AG phosphor, the emission intensity of Dy3+-doped phosphors display stronger owing to the efficient energy transfer from Dy3+ to Tb3+. The optimal amount of Dy3+ in GdAG:Tb3+/Dy3+ phosphors was determined to be ~2.5 at.% (x=0.025). The GdAG:Tb3+/Dy3+ phosphors developed in present work are expected to be a new type of green phosphor widely used in the lighting and display areas.

Comparison between Solid State Reaction and Coprecipitation Method of Titanium Oxide Addition on the YBa2Cu3Oδ Ceramics

2020 ◽  
Vol 1010 ◽  
pp. 187-193
Author(s):  
Ali Arlina ◽  
Nadiah Ameram ◽  
Nik Alnur Auli
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Sem Images ◽  
Orthorhombic Crystal Structure ◽  
Oxide Addition ◽  
Co Precipitation

In this work, comparison of TiO2 additions on the physical properties of YBa2Cu3Oδ superconductor system with nominal starting compositions at x= 0, 1, 2, and 5 wt.% was studied derived via solid state reaction and co-precipitation method. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result from XRD shown that all the samples were polycrystalline for solid state reaction, while single phase appear for co-precipitation methods. The intensity of the peak become higher with increasing amount of TiO2 addition indicating the presence of increased amount of the unreacted in the samples. The refine lattice parameters indicated that all the samples have an orthorhombic crystal structure without occurrence of orthorhombic-tetragonal phase transformation. Furthermore, from SEM images for solid state reaction and co-precipitation method showed that the grain size of the samples decreased with TiO2 increased. Small addition of TiO2 derived from co-precipitation method enhanced the YBCO microstructures.

scholarly journals Photoluminescence (PL) properties of NaLi2PO4:Eu3+ phosphor for solid state lighting application

YMER Digital ◽  
2021 ◽  
Vol 20 (11) ◽  
pp. 91-98
Author(s):  
V.R. Panse ◽  
Keyword(s):  
Solid State ◽  
Solid State Lighting ◽  
Prepared Phosphor ◽  
Diffusion Method ◽  
Solid State Diffusion ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
State Diffusion ◽  
Lighting Application

The polycrystalline NaLi2PO4:xEu (x=0.001,0.002,0.005,0.01 and 0.02) phosphors were successfully synthesized via modified solid state diffusion method [MSSDM]. The structural of prepared phosphor was confirmed by using XRD (X-ray diffraction) technique. Additionally, the photoluminescence (PL) behaviors of NaLi2PO4:xEu phosphor was studied.The XRD pattern of prepared phosphor is well matched with JCPDS file.The PL excitation of prepared phosphor was monitored at 618nm while emission was monitored at 393 nm. The effect of different concentrations of Eu3+ ions in NaLi2PO4 phosphor was studies and optimum PL intensity was obtained at x=0.005 mol. of Eu3+ ion. The CIE co-ordinates were calculated and obtained in orange- red region.

Transition Metal (Ni) Doped SnO2 Nanoparticles Synthesized by Co-Precipitation Method

2019 ◽  
Vol 17 (12) ◽  
pp. 919-923
Author(s):  
S. Maheswari ◽  
M. Karunakaran ◽  
K. Kasirajan ◽  
P. Boomi
Keyword(s):  
Transition Metal ◽  
Band Gap ◽  
Sno2 Nanoparticles ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Ni Doping ◽  
Sem Image ◽  
Agglomeration Process ◽  
Vis Spectroscopy ◽  
Co Precipitation

In this work, we have been reported the transition metal (Ni) doped SnO2 nanoparticles were successfully prepared by chemical co-precipitation method with various Ni doping concentrations such as 0%, 2% and 4%. The prepared Ni doped SnO2 nanoparticles characterized by X-ray diffraction pattern (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis Spectroscopy and Photoluminescence Spectroscopy (PL). The XRD Pattern confirms the presence of polycrystalline nature with the tetragonal structure of SnO2 and the peaks are identified with the JCPDS card No. 88-0287. The SEM image indicates that the particles were irregular shape for all prepared samples. The SEM image showed that the agglomeration process is occurring slowly down with the inclusion of Ni doping content. An EDX study confirms the presence of Sn, O and Ni elements. In FTIR studies the functional groups were identified based on host and doping materials. The minimum band gap value obtained for 0% Ni concentration. When the doping concentration increases, band gap also increases. From PL studies strong band orientation was observed.

scholarly journals COPPER HEXACYANOFERRATE (II): SYNTHESIS, CHARACTERIZATION, AND CESIUM, STRONTIUM ADSORBENT APPLICATION

2021 ◽  
Author(s):  
Dinh Trung Nguyen ◽  
Vu Tram Anh Le ◽  
Dong Phuong Truong ◽  
Thi Dan Thy Kieu ◽  
Tran Thuy Hong Nguyen ◽  
...  
Keyword(s):  
Low Cost ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Copper Hexacyanoferrate ◽  
X Ray ◽  
Transmission Electron ◽  
High Concentrations ◽  
Co Precipitation

Low-cost nanoscale copper hexacyanoferrate (CuHF), a good selective adsorbent for cesium (Cs+) removal, was prepared using the chemical co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) were conducted to determine the CuHF morphology. Copper hexacyanoferrate, Cu13[Fe(CN)6]14.(2K).10H2O, has a cubic structure (space group F-43m) in the range of 10-30 nm and a Brunauer-Emmett-Teller (BET) surface area of 462.42 m2/g. The removal of Cs+ and Sr2+ is dependent on pH; the maximum adsorption capacity (qmax) of CuHF is achieved at a pH = 6. From the Langmuir model, qmax = 143.95 mg/g for Cs+ and 79.26 mg/g for Sr2+, respectively. At high concentrations, Na+, Ca2+, and K+ ions have very little effect on Cs+ removal, and Na+ and K+ ions have a higher affinity for removing Sr2+ than Ca2+ at all concentrations. CuHF has a high affinity for alkaline cations in the order: Cs+ > K+ > Na+ > Ca2+ > Sr2+, as proposed and discussed.

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

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