scholarly journals Magnetic Nanoparticles of Zinc/Calcium Ferrite Decorated with Silver for Photodegradation of Dyes

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3582 ◽  
Author(s):  
Ricardo J. C. Fernandes ◽  
Carlos A. B. Magalhães ◽  
Carlos O. Amorim ◽  
Vítor S. Amaral ◽  
Bernardo G. Almeida ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Optical Band Gap ◽  
Magnetic Measurements ◽  
Ferrite Nanoparticles ◽  
Calcium Ferrite ◽  
Size Estimation ◽  
Visible Absorption ◽  
Uv Visible ◽  
Calcium Ferrites ◽  
Reactive Red 195

Magnetic nanoparticles of zinc/calcium ferrite and decorated with silver were prepared by coprecipitation method. The obtained nanoparticles were characterized by UV/Visible absorption, XRD, TEM and SQUID. The mixed zinc/calcium ferrites exhibit an optical band gap of 1.78 eV. HR-TEM imaging showed rectangular nanoplate shapes with sizes of 10 ± 3 nm and aspect ratio mainly between 1 and 1.5. Magnetic measurements indicated a superparamagnetic behavior. XRD diffractograms allowed a size estimation of 4 nm, which was associated with the nanoplate thickness. The silver-decorated zinc/calcium ferrite nanoparticles were successfully employed in the photodegradation of a model dye (Rhodamine B) and industrial textile dyes (CI Reactive Red 195, CI Reactive Blue 250 and CI Reactive Yellow 145). The nanosystems developed exhibited promising results for industrial application in effluent photoremediation using visible light, with the possibility of magnetic recovery.

scholarly journals Photodeposition of Silver on Zinc/Calcium Ferrite Nanoparticles: A Contribution to Efficient Effluent Remediation and Catalyst Reutilization

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 831
Author(s):  
Ricardo J. C. Fernandes ◽  
Carlos A. B. Magalhães ◽  
Ana Rita O. Rodrigues ◽  
Bernardo G. Almeida ◽  
Ana Pires ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Significant Loss ◽  
Ferrite Nanoparticles ◽  
Calcium Ferrite ◽  
Gel Method ◽  
Magnetic Recovery ◽  
Mixed Ferrite ◽  
Calcium Ferrites

The efficient photodegradation of textile dyes is still a challenge, especially considering resistant azo dyes. In this work, zinc/calcium mixed ferrite nanoparticles prepared by the sol–gel method were coupled with silver by a photodeposition method to enhance the photocatalytic potency. The obtained zinc/calcium ferrites are mainly cubic-shaped nanoparticles sized 15 ± 2 nm determined from TEM and XRD and an optical bandgap of 1.6 eV. Magnetic measurements indicate a superparamagnetic behavior with saturation magnetizations of 44.22 emu/g and 27.97 emu/g, respectively, for Zn/Ca ferrite and Zn/Ca ferrite with photodeposited silver. The zinc/calcium ferrite nanoparticles with photodeposited silver showed efficient photodegradation of the textile azo dyes C.I. Reactive Blue 250 and C.I. Reactive Yellow 145. Subsequent cycles of the use of the photocatalyst indicate the possibility of magnetic recovery and reutilization without a significant loss of efficiency.

scholarly journals A New Non-Centrosymmetricorganotin (IV) Hybrid Compound C5H14N2 [SnCl6] 2H2O: Crystal Structure And Optical Study Characterization

2021 ◽  
Author(s):  
Nejeh Hannachi ◽  
Thierry ROISNEL ◽  
Faouzi HLEL
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Optical Band Gap ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Hybrid Compound ◽  
Visible Absorption ◽  
X Ray ◽  
Uv Visible ◽  
Absorption Measurements

Abstract A new non-centrosymmetricorganotin (IV) hybrid compoundC5H14N2 [SnCl6] 2H2O was determined by single crystal X-ray diffraction at 150(2) K. Its crystal structure was solved by single crystal X-ray diffraction reveling that compound crystallizes in the orthorhombic system with Pbca space group with the following lattice parameters: a = 12.1486 (15) Å, b= 15.4571 (17) Å, c = 16.7610 (18) Å with Z = 8. The bonding between inorganic and organic entities in the compounds is realized by hydrogen bonding O−H…O ,O−H…Cl , NH • • • Cl, N-H…Cl and O−H…Cl. Finally,UV-visible absorption measurements exhibit two absorption bands (226 nm and 262 nm).The optical band gap (Eg) is deduced to be 3.46 Ev.

Synthesis and Characterization of Nickel Oxide Nanostructures by Hydrothermal Method

2018 ◽  
Vol 24 (8) ◽  
pp. 5691-5694 ◽  
Author(s):  
D Sathisha ◽  
K. Gopalakrishna Naik
Keyword(s):  
Nickel Oxide ◽  
Hydrothermal Method ◽  
Optical Band Gap ◽  
Volume Ratio ◽  
Band Gap Energy ◽  
Visible Absorption ◽  
Oxide Nanostructures ◽  
Water As Solvent ◽  
Uv Visible

Nickel oxide (NiO) nanostructures were synthesized by hydrothermal method using ethylene glycol and double distilled water as solvent in 3:2 volume ratio. The synthesized nanostructures were characterized by XRD, FESEM, EDX, FTIR, and UV-visible spectroscopy. XRD result shows that the synthesized nanostructures are polycrystalline in nature. FESEM images show the growth of NiO nanowires. The elemental compositions of the samples were analyzed by EDS. Fourier transform infrared (FTIR) spectroscopy confirms the existence of Ni–O bond in the sample. Optical band gap energy of about 3.71 eV was calculated from the UV-visible absorption measurement.

scholarly journals Effect of Molar Ratio on Structural and Size of ZnO/C Nanocomposite Synthesized Using a Colloidal Method at Low Temperature

2019 ◽  
Vol 19 (2) ◽  
pp. 422
Author(s):  
Siham Lhimr ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Bouchaib Ammary ◽  
...  
Keyword(s):  
Room Temperature ◽  
Optical Band Gap ◽  
Hexagonal Wurtzite Structure ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Colloidal Method ◽  
Uv Visible ◽  
Diffraction Patterns

In this paper we study the effects of different molar ratio R of Zn2+ to OH– (R= nOH–/nZn(II) of the precursor was investigated by varying the amount of NaOH. Samples have been synthesized by the colloidal method at room temperature using (ZnCl2), citric acid (C6H8O9·H2O) and sodium hydroxide (NaOH). The formation of ZnO/C composite was characterized by The X-ray diffraction patterns indicated a high crystallinity and nanocrystalline size of ZnO with hexagonal wurtzite structure. The morphologies of the particles have been studied with a scanning electronic microscopy (SEM). The existence of carbon into the composite was detected by FTIR and EDS. The optical band gap of various ZnO/C composite was calculated from UV-Visible absorption measurement varied in the range 3.301 to 3.282 eV according to R values.

scholarly journals Tuning the Refractive Index and Optical Band Gap of Silk Fibroin Films by Electron Irradiation

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
S. Asha ◽  
Y. Sangappa ◽  
Sanjeev Ganesh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Silk Fibroin ◽  
Structural Changes ◽  
Optical Band Gap ◽  
Dielectric Constants ◽  
Visible Absorption ◽  
Optical Responses ◽  
Uv Visible

TheBombyx morisilk fibroin (SF) films were prepared by solution casting method and effects of electron beam on the optical properties and optical constants of the films have been studied by using UV-Visible spectrophotometer. Optical properties like optical band gapEg, refractive indexn, extinction coefficientk, optical conductivityσopt, and dielectric constantsε∗of virgin and electron irradiated films were determined by using UV-Visible absorption and transmission spectra. It was found that the reduction in optical band gap and increase in refractive index with increasing radiation dosage was observed. It is also observed from results that there is increase in dielectric constants with increasing photon energy. The observed optical changes have been tried to be correlated with the structural changes, revealed through FT-IR spectroscopy. The present study is quite important for tailoring the optical responses of SF films as per specific requirements.

Synthesis and Characterization of the Nano Semiconducting Material Cadmium Sulphide

2011 ◽  
Vol 699 ◽  
pp. 79-88
Author(s):  
S. Santhosh Kumar Jacob ◽  
Saravananakumar S. ◽  
R. Saravanan
Keyword(s):  
Optical Band Gap ◽  
Energy Gap ◽  
Cadmium Sulphide ◽  
Nano Particles ◽  
Precipitation Method ◽  
Nano Materials ◽  
Visible Absorption ◽  
X Ray ◽  
Uv Visible

In this work, CdS nano particles were synthesized using aqueous precipitation method; This method is simple, fast and can be carried out at room temperature. Various techniques like X-ray powder diffraction and UV-visible absorption spectroscopy are used for the structural characterization like electron density distribution and estimation of inter atomic distances between the atoms of the nano particles. The optical band gap of this material has been determined in order to establish a relationship between energy gap of bulk and nano materials.

Optical Properties and Structural Studies on Nd3+ Doped Borate Glasses Containing Heavy Metal Oxide

2012 ◽  
Vol 584 ◽  
pp. 207-211 ◽  
Author(s):  
Vijaya Chikkaveeraiah Veeranna Gowda ◽  
K.R Sardar Pasha ◽  
M. Sudhakar Reddy ◽  
C. Narayana Reddy
Keyword(s):  
Optical Band Gap ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Absorption Studies ◽  
Amorphous Nature ◽  
Uv Visible ◽  
Quenching Method ◽  
Bi2o3 Content

Abstract. Neodymium doped sodium bismuth borate (Na2O-Bi2O3-B2O3) glasses were prepared by melt quenching method. Amorphous nature of the glass is confirmed through the X-ray diffraction study. Density of the investigated glasses increases systematically with Bi2O3 concentration. Glass transition temperature decrease slightly with increase of Bi2O3 content and could be due to increase in the number of weaker Bi-O linkages by stronger Nd-O linkages. Fourier Transform - Infrared (FTIR) spectroscopy has been carried out. The IR spectra of the glasses reveal that the strong network consisting of diborate units and is unaffected by the variation of Nd3+ concentration. UV-Visible absorption studies have been performed on these glasses to examine the optical spectra and the optical band gap energy has been calculated. The intensity of the absorption band increases with the increase of Nd3+ concentration. This is due to the formation of non-bridging oxygens (NBO’s) in the structure.

scholarly journals Magnetoliposomes Containing Calcium Ferrite Nanoparticles for Applications in Breast Cancer Therapy

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 477 ◽  
Author(s):  
Pereira ◽  
Cardoso ◽  
Rodrigues ◽  
Amorim ◽  
Amaral ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Therapy ◽  
Fluorescence Emission ◽  
Calcium Ferrite ◽  
Antitumor Drugs ◽  
Breast Cancer Therapy ◽  
Visible Absorption ◽  
Uv Visible ◽  
First Time ◽  
Potential Antitumor

Magnetoliposomes containing calcium ferrite (CaFe2O4) nanoparticles were developed and characterized for the first time. CaFe2O4 nanoparticles were covered by a lipid bilayer or entrapped in liposomes forming, respectively, solid or aqueous magnetoliposomes as nanocarriers for new antitumor drugs. The magnetic nanoparticles were characterized by UV/Visible absorption, XRD, HR-TEM, and SQUID, exhibiting sizes of 5.2 ± 1.2 nm (from TEM) and a superparamagnetic behavior. The magnetoliposomes were characterized by DLS and TEM. The incorporation of two new potential antitumor drugs (thienopyridine derivatives) specifically active against breast cancer in these nanosystems was investigated by fluorescence emission and anisotropy. Aqueous magnetoliposomes, with hydrodynamic diameters around 130 nm, and solid magnetoliposomes with sizes of ca. 170 nm, interact with biomembranes by fusion and are able to transport the antitumor drugs with generally high encapsulation efficiencies (70%). These fully biocompatible drug-loaded magnetoliposomes can be promising as therapeutic agents in future applications of combined breast cancer therapy.

Remarkable kinetic stability of α-thiocarbamoyl substituted 4-methoxybenzylcations

1998 ◽  
Vol 76 (12) ◽  
pp. 1910-1915 ◽  
Author(s):  
Robert A McClelland ◽  
Victoria E Licence ◽  
John P Richard ◽  
Kathleen B Williams ◽  
Shrong-Shi Lin
Keyword(s):  
Key Words ◽  
Strong Interaction ◽  
Rate Constants ◽  
Flash Photolysis ◽  
Visible Absorption ◽  
Methyl Group ◽  
Thioamide Group ◽  
Azide Ion ◽  
Uv Visible ◽  
Leaving Groups

4-Methoxybenzyl cations bearing α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents have been generated photochemically upon irradiation of precursors with pentafluorobenzoate or 4-methoxybenzoate leaving groups. The ions have been observed with flash photolysis in 40:60 acetonitrile:water and in 50:50 methanol:water, and rate constants were measured for their decay in solvent alone and for their capture by azide ion. The cations so studied and their lifetimes in 40% acetonitrile are 6, ArC+H-CONMe2, 0.6 μs; 2, ArC+H-CSNMe2, 7 ms; and 4, ArC+(CH3)-CSMe2, 6 ms, where Ar = 4-MeOC6H4. The cation 4 reacts with solvent by elimination of a proton from the α-methyl group, and the rate constant for solvent addition must be less than 1 s-1. The CSNMe2 substituted cations are 105-107-fold longer lived than analogs where the thioamide group has been replaced with an α-methyl. The UV-visible absorption spectra of these two cations also show significant differences from those of typical 4-methoxybenzyl cations. Thus, both the lifetimes and spectra point to a strong interaction of the benzylic centre with the thioamide group. Key words: flash photolysis, thiocarbamoyl stabilized carbocation, photosolvolysis.

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