scholarly journals Structural and optical properties of NiO and Mn doped NiO nanparticles

2020 ◽  
Vol 1 (1) ◽  
pp. 20-30
Author(s):  
C. Thangamani ◽  
S.Revathi ◽  
P. Matheswaran ◽  
K. Pushpanathan
Keyword(s):  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Precipitation Method ◽  
Average Crystalline Size ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Optical Microstructure ◽  
Mn Doped ◽  
Fcc Structure ◽  
Microstructure And Magnetic Properties

Ni1-xMnxO (x = 0.0 - 0.05) nanoparticles were successfully prepared by precipitation method at room temperature Prepared samples were characterized by structural, optical, microstructure and magnetic properties. X-ray diffraction analysis confirmed that Mn ions substitution of NiO lattice with FCC structure. The average crystalline size found to decrease from 42 to 34 nm. Optical analysis show increase in band from 4 -3.8 eV by strong quantum confinement effect with blue shift in the absorption spectra range of 325 – 290 nm. FTIR spectra confirmed the formation of Ni-Mn-O.

scholarly journals Optical Studies of Organically Functionalized Mn doped ZnS Quantum Dots

2021 ◽  
Vol 33 (12) ◽  
pp. 2972-2976
Author(s):  
Anju Bala ◽  
Rajeev Sehrawat ◽  
Renu Bala ◽  
Ashutosh Dixit
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Emission Spectra ◽  
Blue Shift ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Uv Visible ◽  
Mn Doped

Organically functionalized manganese doped zinc sulfide (ZnS/Mn) quantum dots were prepared by simple chemical method with polypyrrole (PPy) used as a capping agent. Prepared quantum dots were characterized with Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction microscope (XRD), UV-visible spectroscopy and photoluminescence spectroscopy. Crystalline size of PPy capped ZnS/Mn quantum dots for various concentrations of PPy were approximate 2 nm as analyzed by XRD and TEM analysis. The absorption spectra revealed the occurrence of a blue shift in the peak of absorption and an increase in the band gap value due to the quantum confinement effect. FTIR spectroscopy confirmed that shifting of broad peak at 2335.8 cm–1 was due to S-H stretching vibrations, which confirmed interaction of hydrogen and sulphur in ZnS/Mn/PPy nanocomposites. Uncapped ZnS/Mn and PPy capped ZnS/Mn quantum dots reveal the effective photoluminescence emission spectra in the range of 300-700 nm. With increase the value of capping agent in ZnS/Mn quantum dots, photoluminescence spectra going to red shifting. The photoluminescence properties of the organically functionalized ZnS nanoparticles are favourable for the application in optoelectronic devices.

scholarly journals Fast and Effective Catalytic Degradation of an Organic Dye by Eco-friendly Capped ZnS and Mn doped ZnS nanocrystals

2021 ◽  
Author(s):  
Sabri Ouni ◽  
Naim Bel Haj Mohamed ◽  
Noureddine Chaaben ◽  
Adrian Bonilla-Petriciolet ◽  
Mohamed Haouari
Keyword(s):  
Statistical Physics ◽  
Thioglycolic Acid ◽  
Dye Degradation ◽  
Low Cost ◽  
Quantum Confinement Effect ◽  
Dye Adsorption ◽  
Blue Shift ◽  
Order Kinetic ◽  
Zns Nanocrystals ◽  
Mn Doped

Abstract Undoped and Mn-doped ZnS nanocrystals encapsulated with thioglycolic acid were synthetized and characterized with different techniques, and finally tested in the photodegradation of a methyl orange in aqueous solution under UV and sunlight irradiations. FTIR and X-ray diffraction results confirmed the functionalization of these nanocrystals surface by thioglycolic acid and the formation of crystalline structures of ZnS and Mn-doped ZnS with cubic and hexagonal phases. Calculated average size of ZnS nanocrystals was in the range of 2 - 3 nm. It was observed a blue shift of the absorbance threshold and the estimated bandgap energies were higher than that of Bulk ZnS thus confirming the quantum confinement effect of charge carriers. Photoluminescence spectra of ZnS nanocrystals exhibited emission in the range of 410- 490 nm and the appearance of an additional emission band around 580 nm (2.13eV) connected to the 4𝑇1→ 6𝐴1 transition of the Mn2+ions. Photodegradation of methylene orange with undoped and Mn-doped ZnS-TGA nanocrystals was investigated. Dye adsorption prior to photocatalysis using nanocrystals was studied via kinetic experiments and statistical physics models. The maximum dye adsorption capacity on doped ZnS-TGA was ~ 26.98 mg/g. The adsorption kinetic was found to follow the pseudo-second-order kinetic model.According to the statistical physics results, the calculated adsorption energy was 22.47-23.47 kJ/mol and it showed that the dye adsorption was associated to the hydrogen interaction where the removal process was feasible and multi-molecular. The photocatalytic activity of undoped ZnS nanoparticles under UV irradiation showed better efficiency than doped nanocrystals thus indicating that manganese doping generated a dropping of the photocatalytic degradation of the dye. Dye degradation efficiency of 81.37% using ZnS-TGA nanocrystals was achieved after 6 min, which indicated that ZnMnS-TGA nanocrystals may be considered as an alternative low cost and environmental friendly material for facing water pollution caused by organic compounds via photodegradation processes.

Optical, Structural and Spectroscopic Characterization of ZnS Nanocrystals Embedded in KBr Single Crystal Matrix Grown by Czochralski Method

2021 ◽  
Vol 406 ◽  
pp. 274-284
Author(s):  
Soria Zeroual ◽  
Mohammed Sadok Mahboub ◽  
Ghani Rihia ◽  
Mourad Mimouni ◽  
Ghougali Mebrouk ◽  
...  
Keyword(s):  
Single Crystal ◽  
Absorption Edge ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Czochralski Method ◽  
Spectroscopic Characterization ◽  
Czochralski Growth ◽  
X Ray Diffraction ◽  
Crystal Matrix ◽  
Zns Nanocrystals

ZnS nanocrystals were embedded in a KBr single crystal matrix using the Czochralski growth technique. The X-ray diffraction, FT-IR and optical spectroscopy revealed the incorporation of ZnS nanocrystals. A blue shift of the absorption edge of the obtained samples has been observed, indicating the quantum confinement effect. The optical band-gap is estimated to be about 4.67 eV. Two excitonic peaks appeared at 300.4 nm and 271 nm. The average nanocrystal size was derived from the optical spectra. Annealing led to a shift in the absorption edge towards longer wavelengths and an increasing of the emissions intensity. Raman lines of the nanoparticles are broader and frequency-shifted compared to those of the bulk crystals. These results show that KBr is a good matrix-host of ZnS nanocrystals, and that the elaborated samples can be used for important technological applications.

Synthesis of Zn Doped CdSe Quantum Dots via Inverse Micelle Technique

2014 ◽  
Vol 807 ◽  
pp. 115-121 ◽  
Author(s):  
Fatihah Aplop ◽  
Mohd Rafie bin Johan
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Cdse Qds ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Inverse Micelle ◽  
Cadmium Selenide Quantum Dots ◽  
The Fourier Transform

Zinc doped Cadmium Selenide Quantum Dots (CdSe/Zn QDs) were synthesized via inverse micelle technique. The absorption spectra exhibit a strong blue-shift characteristic due to quantum confinement effect. The X-ray Diffraction (XRD) pattern showed the zinc-blende phase of Zn doped CdSe QDs. Transmission Electron Microscopy (TEM) images suggested that the sizes of QDs were falls in range between 2 – 8 nm, with narrow size distribution. The TEM images also revealed that the Zn doped CdSe QDs were spherical, having a compact and dense structure. The optical bandgap of Zn-doped CdSe QDs are smaller than the undoped CdSe QDs as shown in Tauc’s plot. The fourier transform infrared spectra proves the complexion of CdSe-Zn QDs.

Synthesis and Characterization of Pure and Mn Doped Zinc Sulphide Nanoparticles and Nanofluids

2015 ◽  
Vol 1086 ◽  
pp. 101-106
Author(s):  
M. Gopalakrishnan ◽  
Issac P. Nelson ◽  
Solomon Jeevaraj A. Kingson
Keyword(s):  
Morphological Structure ◽  
Blue Shift ◽  
Chemical Precipitation ◽  
Zinc Sulphide ◽  
Precipitation Method ◽  
Average Particle ◽  
Zns Nanoparticles ◽  
Pure Zinc ◽  
Yellow Orange ◽  
Mn Doped

In this work, pure ZnS and Mn doped ZnS nanoparticles are synthesized by simple chemical precipitation method. The structure of pure zinc sulphide and Mn doped zinc sulphide sample are analyzed by X-ray diffraction technique. The morphological structure of zinc sulphide and Mn2+doped zinc sulphide nanoparticles are studied using scanning electron microscope (SEM). The average particle sizes of pure ZnS nanoparticles are determined to be from 29 nm to 44 nm and Mn doped ZnS nanoparticles are determined to be from 99 nm to 135 nm. The optical properties of pure and Mn doped ZnS nanoparticles have been investigated by photoluminescence (PL) spectroscopy. The emission spectrum of Mn2+doped with ZnS particles of the present study shows blue shift of the yellow-orange emission peak at 590 nm. Nanofluids are prepared for six different concentrations by dispersing pure and Mn2+doped ZnS nanoparticles in de-ionized water. Thermal conductivity studies are carried out for both nanofluid systems and the results are discussed.

scholarly journals Размерно-зависимые оптические свойства коллоидных квантовых точек CdS, пассивированных тиогликолевой кислотой

2018 ◽  
Vol 52 (9) ◽  
pp. 1015
Author(s):  
Т.С. Кондратенко ◽  
М.С. Смирнов ◽  
О.В. Овчинников ◽  
Е.В. Шабуня-Клячковская ◽  
А.С. Мацукович ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Cubic Crystal ◽  
Luminescence Kinetics ◽  
Donor Acceptor ◽  
Colloidal Cds

AbstractThe results of studies of the optical properties of ensembles of colloidal CdS quantum dots passivated by thioglycolic acid are reported. The average dimensions of the quantum dots lie in the range from 1.7 to 5.8 nm. By X-ray diffraction studies and Raman spectroscopy, it is established that quantum dots crystallize with the formation of a cubic crystal lattice. The systematic features of the quantum-confinement effect in the optical absorption and luminescence spectra, as well as in the luminescence excitation spectra, are established. The features manifest themselves as a blue shift of the corresponding bands with decreasing quantum-dot dimensions. From analysis of the nanosecond luminescence kinetics, it is concluded that experimentally observed radiative recombination proceeds by the donor–acceptor mechanism.

scholarly journals Preparation and Characterization of Zno Nano particles Prepared by Hydrothermal Method

2019 ◽  
Vol 24 (3) ◽  
pp. 91
Author(s):  
Mohammed Ajmi Abd1 ◽  
Khalid Hamdi Razeg1 ◽  
Raad M.S Al-haddad2
Keyword(s):  
Quantum Confinement Effect ◽  
Hydrothermal Process ◽  
Blue Shift ◽  
Band Gap Energy ◽  
Zinc Nitrate ◽  
Nano Particles ◽  
Surface Topology ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Afm Analysis

In this study,the nanoparticles of zinc oxide were readily prepared  through Hydrothermal process by using zinc nitrate hexahydrate, and Sodium hydroxide as aprecursors. The surface topology, and crystalline structure of prepared ZnO nanoparticles were studied. X-ray diffraction (XRD) revealed that the prepared ZnO nano particles is highly crystalline, having (wurtzite) crystal structure.  The optical analysis by UV–vis showed that these ZnO nano particles have considerable blue shift in the optical band gap energy (Eg = 4.9eV), and this may be to the  quantum confinement effect of nano particles. The FT-IR results shows the  existence of OH, COO, H2O groups the characteristic vibrational modes of Zn–O were identified. and AFM analysis showed that the diameters of the ZnO particles is in ananometer range of (70-74)nm.   http://dx.doi.org/10.25130/tjps.24.2019.052 

scholarly journals Influence of the sintering temperature on the morphology and structural properties of Ni-Mg substituted of cobalt ferrites

2015 ◽  
Vol 11 (2) ◽  
Author(s):  
R. M. Rosnan ◽  
Zulkafli Othman ◽  
A. A. Ati
Keyword(s):  
Structural Properties ◽  
Spinel Ferrite ◽  
Precipitation Method ◽  
Nominal Composition ◽  
Average Crystalline Size ◽  
X Ray Diffraction ◽  
Cobalt Ferrites ◽  
Phase Spinel ◽  
Co Precipitation ◽  
Good Agreement

This study evaluates the morphology and structural properties of Ni-Mg substituted Cobalt ferrite samples prepared through the co-precipitation method. The nominal composition of Co0.5Ni0.5−xMgx Fe2O4 in the range x = 0.1 have been synthesized and then were sintered at temperature 700 and 1000°C for 10 hour with a heating rate of 5°C/min. The prepared nano-ferrites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 40–120 nm. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.

Effect of Gallium and Indium Co-Substituting on Upconversion Properties of Er/Yb:Yttrium Aluminum Garnet Powders Prepared by the Co-Precipitation Method

2016 ◽  
Vol 16 (4) ◽  
pp. 3517-3521 ◽  
Author(s):  
Wei Zhang ◽  
Yun-Ling Liang ◽  
Zheng-Fa Hu ◽  
Zu-Yong Feng ◽  
Ma Lun ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Infrared Spectra ◽  
Formation Process ◽  
Photoelectron Spectroscopy ◽  
Blue Shift ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermo Gravimetry ◽  
Co Precipitation

Gallium and Indium co-substituted Yb, Er:YAG was fabricated through the chemical co-precipitation method. The formation process and structure of the Ga3+ and In3+ substituted phosphor powders were characterized by the X-ray diffraction, thermo-gravimetry analyzer, infrared spectra, and X-ray photoelectron spectroscopy, and the effects of Ga3+ and In3+ concentration on the luminescence properties were investigated by spectrum. The results showed that the blue shift occurred after the substitution of Ga3+ and In3+ for Al3+ in matrix, and the intensity of emission spectrum was affected by the concentration of Ga3+ and In3+.

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