scholarly journals Photodegradation of Eosin Y Using Silver-Doped Magnetic Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Eman Alzahrani

The purification of industrial wastewater from dyes is becoming increasingly important since they are toxic or carcinogenic to human beings. Nanomaterials have been receiving significant attention due to their unique physical and chemical properties compared with their larger-size counterparts. The aim of the present investigation was to fabricate magnetic nanoparticles (MNPs) using a coprecipitation method, followed by coating with silver (Ag) in order to enhance the photocatalytic activity of the MNPs by loading metal onto them. The fabricated magnetic nanoparticles coated with Ag were characterised using different instruments such as a scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDAX) spectroscopy, and X-ray diffraction (XRD) analysis. The average size of the magnetic nanoparticles had a mean diameter of about 48 nm, and the average particle size changed to 55 nm after doping. The fabricated Ag-doped magnetic nanoparticles were used for the degradation of eosin Y under UV-lamp irradiation. The experimental results revealed that the use of fabricated magnetic nanoparticles coated with Ag can be considered as reliable methods for the removal of eosin Y since the slope of evaluation of pseudo-first-order rate constant from the slope of the plot betweenln⁡(Co/C)and the irradiation time was found to be linear. Ag-Fe3O4nanoparticles would be considered an efficient photocatalyst to degrade textile dyes avoiding the tedious filtration step.

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.


2020 ◽  
Vol 10 (6) ◽  
pp. 7257-7264

Metal nanoparticles are gaining importance nowadays in nanoscience. The nanoparticle had better physical and chemical properties compared with solid particles due to their large surface area. The silver nanoparticles are employed mostly in medical and electrical applications having outstanding conductivity and antimicrobial activity. In the present investigation, NaBH4 and ethanol were used as a reductant and stabilizer agent from silver nitrate salt as a precursor. The silver nanoparticles obtained were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) to determine their morphology and size. In XRD analysis, the average particle size was found to be 18.31 nm. The TEM analysis shows crystalline morphology with a face-centered cubic structure. The antibacterial activity was tested against two bacterial cultures, namely Bacillus subtilis and Pseudomonas aeruginosa. The inhibition zones of 19mm and 17mm were observed against Bacillus subtilis and Pseudomonas aeruginosa, respectively.


1999 ◽  
Vol 14 (5) ◽  
pp. 2023-2028 ◽  
Author(s):  
Ming Fu ◽  
S. Penumella ◽  
J. A. Sekhar

An aluminothermic reaction starting with inexpensive MoO3, SiO2, and Al powders was utilized to prepare molybdenum disilicide (MoSi2) powders by the micropyretic/combustion synthesis process and leaching. The combustion-synthesized product was porous and could readily be crushed into powders. X-ray diffraction (XRD) analysis revealed that the product of such a reaction consisted of α–Al2O3, MoSi2, and a small amount of Mo(Si,Al)2 and Mo5Si3. The reason for the formation of Mo(Si, Al)2 phase is discussed. MoSi2 powders were obtained by leaching out the Al2O3 from the synthesized powder mixtures in boiling phosphoric acid solution. The synthesized MoSi2 powders, including a small amount of Mo(Si, Al)2 and Mo5Si3, were very fine with an average particle size of about 1 μm.


2021 ◽  
Author(s):  
Kanika Dulta ◽  
Gözde Koşarsoy Ağçeli ◽  
Parveen Chauhan ◽  
Rohit Jasrotia ◽  
Gourav Chandan ◽  
...  

Abstract Rhizome extract of Bergenia ciliata was used as a bio-functional reducing material for green synthesis of copper oxide nanoparticles (CuO NPs). CuO NPs were characterized using ultra violet–visible spectroscopy (UV–vis), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). XRD analysis revealed the monoclinic phase of synthesized CuO NPs with average particle size of 20 nm. Spherical shaped nanoscale CuO particles were observed by EDX and SEM confirming the Cu and O presence in the synthesized nanoparticles. CuO nanoparticles showed antibacterial effects against all bacteria used in the study. The antioxidant effect was measured and IC50 values for ABTS, DPPH and FRAP assays were found to be 91.2, 72.4 and 109.0 µg/ mL− 1 respectively. Under sunlight, the CuO NPs reported extraordinary photocatalytic activity against methylene blue and methyl red degradation with efficiencies of 92 and 85 percent, respectively. CuO NPs have excellent potential application for the photocatalytic degradation of organic pollutant and in the development of antibacterial materials and for the first-time effect of these nanoparticles were reported.


2017 ◽  
Vol 46 ◽  
pp. 64-72 ◽  
Author(s):  
Abrham Bayeh Wassie ◽  
Vimal Chandra Srivastava

Efficient utilization of agricultural residue is the need of today’s environment. Teff straw is one such agricultural residue which is available in high amount in east African continent particularly Ethiopia. In the present study, combination of heat and acid treatment has been used to extract nano-silica from teff straw. X-ray fluorescence (XRF) analysis showed presence of high amount of silicon dioxide (≈52%) in raw teff straw. Thermal treatment at 600°C for 4 hour increased the SiO2 concentration to ≈ 92% in its ash. Further acid treatment increased the concentration to ≈97%. Fourier transform infrared (FTIR) spectroscopy also confirmed increase in SiO2 after thermal and acid treatment. X-ray diffraction (XRD) analysis showed the silica of amorphous nature in teff straw ash before acid treatment (S-BAT) whereas crystallinity increased after acid treatment (S-AAT). Transmission electron microscopy (TEM) showed presence of uniform nano-disks shaped particles of 50 nm average particle size in acid treated teff straw ash. Compared to other agricultural residues high amount of silica availability as raw and its small diameter anatomy structure will make teff straw better source of silica material at lower heat and chemical treatment.


2021 ◽  
Vol 8 ◽  
Author(s):  
Klebson Lucenildo Da Silva ◽  
Rafael Santiago Trautwein ◽  
Rodolfo Bezerra Da Silva ◽  
Martin Fabián ◽  
Erik Čižmár ◽  
...  

Bismuth ferrite (BiFeO3) particles are prepared by a combined mechanochemical−thermal processing of a Bi2O3 + α-Fe2O3 mixture. Structural, magnetic, hyperfine, morphological and chemical properties of the as-prepared BiFeO3 are studied using X-ray diffraction (Rietveld refinement), 57Fe Mössbauer spectroscopy, SQUID magnetometry, electron microscopy and energy dispersive X-ray spectroscopy. It is revealed that the structure of the ferrite exhibits the long-range distortion (significantly tilted FeO6 octahedra) and the short-range disorder (deformed FeO6 octahedra). Consequently, these structural features result in the suppression of a space modulated cycloidal spin arrangement in the material. The latter manifests itself by the appearance of only single spectral component in the 57Fe Mössbauer spectrum of BiFeO3. The macroscopic magnetic behavior of the material is interpreted as a superposition of ferromagnetic and antiferromagnetic contributions with a large coercive field and remanent magnetization. Taking into account the average particle size of the as-prepared BiFeO3 particles (∼98 nm), exceeding the typical period length of cycloid (∼62 nm), both the suppression of the spiral spin structure in the material and its partly ferromagnetic behavior are attributed to the crystal lattice distortion caused by mechanical stress during the preparation procedure.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Azariel Díaz-Hernández ◽  
Jorge Gracida ◽  
Blanca E. García-Almendárez ◽  
Carlos Regalado ◽  
Rosario Núñez ◽  
...  

Cross-linking of magnetic nanoparticles with proteins plays a significant role in the preparation of new materials for biotechnological applications. The aim was the maximization of the magnetic mass attracted and protein loading of magnetic iron oxide nanoparticles coated with chitosan, synthesized in a single step by alkaline precipitation. Chitosan-coated magnetite particles (Fe3O4@Chitosan) were cross-linked to a xylanase and a cellulase (Fe3O4@Chitosan@Proteins), showing a 93% of the magnetic saturation of the magnetite. X-ray diffraction pattern in composites corresponds to magnetite. Thermogravimetry and differential scanning calorimetry showed that 162 mg of chitosan was coating one gram of composite and 12 mg of protein was cross-linked to each gram of magnetic support. Cross-linking between enzymes and Fe3O4@Chitosan was confirmed by infrared spectroscopy with Fourier transform, X-ray energy, and X-ray photoelectron spectroscopy dispersion analysis. From dynamic light scattering, transmission and electron microscopy the average particle size distribution was 230 nm and 430 nm for Fe3O4@Chitosan and Fe3O4@Chitosan@Proteins, showing agglomerates of individual spherical particles, with an average diameter of 8.5 nm and 10.8 nm, respectively. The preparation method plays a key role in determining the particle size and shape, size distribution, surface chemistry, and, therefore, the applications of the superparamagnetic nanoparticles.


2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Kanika Dulta ◽  
Gözde Koşarsoy Ağçeli ◽  
Parveen Chauhan ◽  
Rohit Jasrotia ◽  
P. K. Chauhan ◽  
...  

AbstractRhizome extract of Bergenia ciliata was used as a bio-functional reducing material for the green synthesis of copper oxide nanoparticles (CuO NPs). CuO NPs were characterized using ultraviolet–visible spectroscopy, Fourier transforms infrared spectroscopy, X-ray diffraction (XRD), dynamic light scattering, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). XRD analysis revealed the monoclinic phase of synthesized CuO NPs with an average particle size of 20 nm. Spherical shaped nanoscale CuO particles were observed by EDX and SEM confirming the Cu and O presence in the synthesized NPs. CuO NPs showed antibacterial effects against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi. The antioxidant effect was measured and IC50 values for 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power assays were found to be 91.2, 72.4 and 109 μg mL− 1 respectively. Under sunlight, the CuO NPs reported extraordinary photocatalytic activity against Methylene Blue and Methyl Red degradation with efficiencies of 92–85%. CuO NPs have excellent potential application for the photocatalytic degradation of organic pollutants and in the development of antibacterial materials. This study offers new insights in the field of inexpensive and green synthesis-based antimicrobial effective CuO photocatalysts from B. ciliata to remove harmful dyes from industrial-based waters with high degradation efficiency, which is environmentally friendly.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.


2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660002 ◽  
Author(s):  
V. Kavitha ◽  
P. S. Ramesh ◽  
D. Geetha

Copper doped Titanium dioxide TiO2 nanoparticles were synthesized by sol–gel method using titanium tetraisopropoxide and copper sulfate as precursors. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), Photoluminesce spectroscopy (PL) and atomic force microscopy (AFM). XRD analysis confirms the formation of anatase titanium dioxide and average particle size was 35[Formula: see text]nm. Cu– TiO2 exhibits a shift in the absorption edge toward visible spectrum. The rate of recombination and transfer behavior of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. From SEM spherical shaped nanoparticles was observed. Comparing with pure TiO2 nanoparticles, Cu doped TiO2 photocatalyst exhibited enhanced photocatalytic activity under natural sunlight irradiation in the decomposition of rhodamine B aqueous solution. The maximum 97% of degradation efficiency of Rhodamine B was observed at 0.6% Cu–TiO2 within 180[Formula: see text]min. The photocatalytic efficiency of Rhodamine B of Cu doped TiO2 nanoparticle was higher than the pure TiO2, which could be attributed to the small crystallinity intense light absorption in Sunlight and narrow bandgap energy of Copper.


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