Co-Doped ZnO Nano-Agglomerates as a Potential Scaffold for Non-Enzymatic Hydrogen Peroxide Sensing

2021 ◽  
Vol 13 (9) ◽  
pp. 1732-1738
Author(s):  
Ahmad Umar ◽  
Ramesh Kumar ◽  
Rajesh Kumar ◽  
Ahmed A. Ibrahim ◽  
Mohsen A. M. Alhamami ◽  
...  
Keyword(s):  
Hexagonal Phase ◽  
Average Particle Size ◽  
Solution Process ◽  
Average Particle ◽  
Spherical Nanoparticles ◽  
Cyclic Voltammetric ◽  
Wurtzite Hexagonal Phase ◽  
Dynamic Concentration ◽  
Doped Zno ◽  
Co Doped

Co-doped ZnO nano-agglomerates were synthesized by a facile solution process. Several characterization techniques revealed the successful doping of the ZnO by Co ions. FESEM results showed the agglomeration of the Co-doped ZnO nanoparticles to form large-sized nano-agglomerates. The diameters of the spherical nanoparticles and the agglomerates were not found to be uniform. The diameters of the nano-agglomerates ranged from ~25 nm–120 nm. XRD spectrum confirmed the Wurtzite hexagonal phase of ZnO in Co-doped ZnO nanoagglomerates. The average particle size for Co-doped ZnO nano-agglomerates was 20.68 nm. The sensing parameters were examined by using Co-doped ZnO nano-agglomerates modified gold electrode through cyclic voltammetric and amperometric analysis. The sensitivity of 70.73 μAmM−1cm−2 and very low-detection limit of 0.2 μM was observed for H2O2. The corresponding linear dynamic concentration range was 0.2–1633 μM. The excellent sensing activities of the Co-doped ZnO nano-agglomerates for H2O2 were attributed to the improved intrinsic electric properties and increased inner defects density, particularly near the interface region.

scholarly journals Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Semiconductor Nanoparticles ◽  
Nano Particles ◽  
Average Particle ◽  
Rare Earth Ion ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

scholarly journals Photocatalytic and Photoluminescence Studies of La, Ce and Dy Co-Doped ZnO Nanoflowers

2021 ◽  
Author(s):  
Syed Irtiqa ◽  
Atikur Rahman
Keyword(s):  
Zno Nanoparticles ◽  
Photocatalytic Performance ◽  
Average Particle Size ◽  
Visible Region ◽  
Solar Spectrum ◽  
Grain Morphology ◽  
Average Particle ◽  
Trap States ◽  
Doped Zno ◽  
Co Doped

Abstract In the present work, ZnO nanoparticles were doped with varying concentration of Lanthanum (La), Cerium (Ce) and Dysprosium (Dy) using a simple and cost effective co-precipitation approach at low temperatures. The resulting powders were calcined at 500 °C for 1 hour using a muffle furnace, to produce La, Ce, Dy co-doped ZnO nanoparticles with varying stoichiometry viz. Zn0.97La0.01Ce0.01Dy0.01O, Zn0.94La0.02Ce0.02Dy0.02O, Zn0.91La0.03Ce0.03Dy0.03O, Zn0.88La0.04Ce0.04 Dy0.04O and Zn0.85La0.05Ce0.05Dy0.05O. This is a simple approach for doping and doesn’t require and complex equipment, harmful chemical or sophisticated machinery. The synthesized powders were characterized using X-Ray diffraction (XRD) and Scanning electron microscopy (SEM) for studying the structure, purity, and grain morphology. The average particle size was calculated using XRD and was found to be 35 nm, it also indicated a hexagonal wurtizite structure with no secondary peaks. A change in morphology from nanorods to nanoflowers was observed as the concentration of dopants increased. Photoluminescence (PL) spectra indicated a red shift in the absorption edge towards the visible region of solar spectrum and this was further confirmed by Diffuse Reflectance Spectra (DRS). The photocatalytic properties of undoped and La, Ce, Dy co-doped ZnO nanoparticles were observed by examining the photodegradation of Rhodamine B dye under UV irradiation. Elimination of dye color indicated the total degradation of organic molecule. The results revealed that ZnO photocatalyst with La, Ce, Dy co-doping concentration Zn0.85La0.05Ce0.05Dy0.05O exhibited the best photocatalytic performance (95%) as compared to undoped ZnO. The improved photocatalytic performance can be attributed to the increased surface oxygen vacancies and adsorption capacity. Delay in recombination of charge carriers due to creation trap states in the bandgap of ZnO further improves the photocatalytic performance of doped samples.

scholarly journals Potfrigator Technology : Preservatives Equipment Low Energy For Fish and Reducing Hazardous Heavy Metals Based Photocatalytic Co Doped ZnO and Cooling Dynamic System

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 16
Author(s):  
Alfin Darari ◽  
Mukholit . ◽  
Arif Sony Wibowo
Keyword(s):  
Heavy Metals ◽  
Zno Nanoparticles ◽  
Cooling System ◽  
Average Particle Size ◽  
Homogeneous Solution ◽  
The Body ◽  
Average Particle ◽  
Body Tissues ◽  
Doped Zno ◽  
Co Doped

<p>Pollution is caused by dangerous heavy metal such as Pb, Cu and Zn are toxic in the body tissues of organisms such as fish in high concentrations, it will be harmful to human health The purpose is to create an eco-friendly fish preservative tool with cooling system of thermodynamics and photocatalytic Co doped ZnO nanoparticles. this device can reach temperature 15 oC. Then to reduce dangerous heavy metals and kill bacteria used principle of photocatalytic Co doped ZnO nanoparticles. Co doped ZnO synthesized by sol-gel method. Then proceeded to spray coating and drying with furnace. The result is a purple clear homogeneous solution. From the analysis of the obtained bandgap Co doped ZnO about 2.28 eV and from SEM generated that average particle size Co doped ZnO is 60 nm. From the result of Co doped ZnO can be initiated by visible light and may have antibacterial activity so that this material can be made as a tool to prevent the growth of microorganisms only using regular light </p><p><strong>Key words</strong> : Eco-friendly fish preservative tools; less energy based on cooling dynamic; Nano Co Doped ZnO. <br /><br /></p>

Structural and Morphological Properties of Ag and In Co-Doped ZnO Nanoparticles Synthesized by Sol-Gel Method

2017 ◽  
Vol 17 ◽  
pp. 101-105 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
Durairaj Benny Anburaj ◽  
G. Nedunchezhian ◽  
R. Meenambika
Keyword(s):  
Zno Nanoparticles ◽  
Sol Gel ◽  
Average Particle Size ◽  
Morphological Properties ◽  
Average Particle ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno ◽  
Co Doped

Zinc oxide has been receiving an enormous attention due to its potential applications in a variety of field such as optoelectronics, spintronics and sensors. Ag and In co-doped ZnO nanoparticles with different doping concentration 0.1M, 0.2M and 0.3M were prepared by sol-gel method via microwave irradiation followed by calcinations at 600°C for 2h. The structure and morphology were examined by X-ray diffraction (XRD), and Scanning Electron Microscope (SEM), respectively. Elemental composition has been estimated by Energy Dispersive X-ray Absorption (EDAX), while chemical properties are studied by Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) . The average particle size of the synthesized ZnO nanoparticles was calculated using the Scherrer formula and is found to be of less than 20 nm. Also the effect on the structure and the morphological properties of ZnO when co-doped with silver and Indium is examined. As the process is simple and low cost, it has the potential to be produced on a large scale.

scholarly journals Facile Microemulsion Synthesis of Vanadium-Doped ZnO Nanoparticles to Analyze the Compositional, Optical, and Electronic Properties

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 821 ◽  
Author(s):  
H.S. Ali ◽  
Ali Alghamdi ◽  
G. Murtaza ◽  
H.S. Arif ◽  
Wasim Naeem ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Attenuated Total Reflection ◽  
Lattice Parameters ◽  
Average Particle ◽  
Structural Morphology ◽  
Wurtzite Phase ◽  
X Ray ◽  
Doped Zno

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.

Minimum Particle Diameter of the Vanadium/Iron Co-Doped Nano TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 989-994 ◽  
pp. 611-614
Author(s):  
Ling Li ◽  
Wen Ming Zhang ◽  
Hua Yan Zhang ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Ferric Nitrate ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Vanadium Iron ◽  
Co Doped

Vanadium/iron co-doped nanoTiO2 transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, ferric nitrate, ammonium metavanadate, etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, EDS, nanolaser particle size analyzer, and UV-Vis spectrophotometer. The photocatalytic properties of V/Fe doped TiO2 were studied through degrading acid 3R dye, and the results show that when the content of V/Fe was 0.5%, the degradation rate reached more than 96% under irridation for 60 min.

Blue Fluorescence in Doped LaF3 Nanocrystals Synthesized by Microwave Technique

2012 ◽  
Vol 584 ◽  
pp. 219-223
Author(s):  
S.G. Gaurkhede ◽  
M.M. Khandpekar ◽  
S.P. Pati ◽  
A.T. Singh
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Hexagonal Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Blue Fluorescence ◽  
Tem Analysis ◽  
Selected Area Electron Diffraction ◽  
20 Nm

Hexagonal-phase LaF3: Ce3+, Pr3+, and Sm3+ doped (LCPS) nano-crystals have been synthesized by keeping same molarities of rare earth elements using aqueous route. The samples have been synthesized in conventional microwave on low power range in about an hour’s time. The phase formation has been verified by powder X-ray diffraction (XRD).Hexagonal geometry of the LCPS nano-crystals has been observed with an average particle size of 20 nm by TEM analysis. The JCPDS Card No. (32-0483) and selected area electron diffraction (SAED) pattern has been used for identification of crystal structure. The UV- VIS spectra indicated band gap of 5.00eV. The FTIR spectrums have been used for assignment of fundamental vibrations. Blue fluorescence observed with exciting wavelengths of 254 nm respectively. The presence of rare-earth elements in LCPS nano-crystals have been verified by the EDAX spectra.

The concentration quenching of photoluminescence in Eu3+-doped La2O3

2013 ◽  
Vol 37 (1) ◽  
pp. 47-54 ◽  
Author(s):  
V. Đorđević ◽  
Ž. Antić ◽  
M. G. Nikolić ◽  
M. D. Dramićanin
Keyword(s):  
Room Temperature ◽  
Hexagonal Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Lifetime ◽  
Transmission Electron ◽  
Lifetime Value ◽  
Kinetics Of

Abstract This work explores the influence of dopant concentration on photoluminescent emission and kinetics of Eu3+-doped (0.2−10 at.%) nanocrystalline lanthanumoxide powders. The X-ray diffraction analysis confirmed that all samples crystallize in La2O3 hexagonal phase with space group P3¯ m1. Transmission electron microscopy showed particles with non-uniform shape and diverse size distribution with an average particle size of (95 ± 5) nm. The room temperature photoluminescence spectra of all samples contain characteristic Eu3+ luminescence lines with the most pronounced red 5D0 →7F2 emission at about 626 nm. The maximum intensity of red emission is observed for the sample containing 5at.% of Eu3+ ions. The emission kinetics was recorded in the temperature range from 10K to 300 K. The maximum lifetime value of 0.98 ms obtained for the sample with 0.5at.% Eu3+ at room temperature increases up to 1.3ms at 10 K.

scholarly journals Synthesis and Study of Microcrystalline Parameters with Electrical Conductivity of Al Doped Lithium Ferrites

2017 ◽  
Vol 14 (2) ◽  
pp. 185-189
Author(s):  
Suresh. S Darokar
Keyword(s):  
Mass Density ◽  
Hexagonal Phase ◽  
Average Particle Size ◽  
Solid State Reaction Method ◽  
Average Particle ◽  
Ferrous Ions ◽  
Xrd Pattern ◽  
Lithium Ferrites ◽  
General Chemical ◽  
Ray Density

Magnetoplumite type of lithium ferrites substituted by aluminium ions having general chemical formula Li0.5Fe0.5+xAl12-X O19 (where x = 1 to 6) were prepared by standard solid state reaction method The compounds are in single hexagonal phase without traces of uncertainly ambiguous reflection. From XRD pattern lattice parameters has recorded with increasing doped aluminium element in the range from a = 5.807 Å to 5.906 Å and c = 22.507 Å to 22.585 Å pertaining the space group P63/mmc (No.194). The mass density of the ferrites were found linearly varies and depends upon the mass and volume of sample. The X-Ray density has depends upon the lattice constant and molecular weight of the compounds. The average particle size was also estimated. Electrical properties such as dc conductivity, activation energy were studied. Also, the type of carriers responsible in each was determined from thermoelectric studies. The higher resistivity of the compounds Li0.5Fe0.5+xAl12-X O19 suggests less presence of mixed valency cations on equivalent lattice. While Fe show low value due to the ferrous ions present on the octahedral sites along with ferric ions.

scholarly journals Effect of Mn Doping on The Structural, Optical, Magnetic Properties and Antibacterial Activity of ZnO Nanospheres

2021 ◽  
Author(s):  
EBENEZAR JEYASINGH ◽  
Kelvin Adaikalam Charles ◽  
Pandiyarajan Thangaraj ◽  
Karthikeyan Chandrasekaran ◽  
Mangalaraja Ramalinga Viswanathan
Keyword(s):  
Zinc Oxide ◽  
Oxygen Vacancies ◽  
Average Particle Size ◽  
Antibacterial Properties ◽  
Ferromagnetic Phase ◽  
Average Particle ◽  
Zno Nps ◽  
Mn Doping ◽  
Doped Zno ◽  
Mn Doped

Abstract In this work, a systematic study of structural, optical, magnetic and antibacterial properties of Mn doped ZnO has been investigated. Zinc oxide (ZnO) and Mn2+ doped zinc oxide (ZnMnO) nanoparticles (NPs) were prepared through co-precipitation method. The X-ray diffraction studies confirmed that the synthesize nanoparticles did not modify the crystal structure upon Mn doping, but the microstructural parameters were changed considerably while increasing the concentration of Mn dopant. The HRTEM images showed that the ZnO NPs were exhibited nanospheres like morphology and a reduction in the average particle size from 41 nm to 33 nm were observed upon Mn2+ doping. The elemental composition of Zn, Mn and O atoms were identified by EDAX spectra. The Zn-O stretching bands were observed at 539 and 525cm-1 in the FTIR spectra and, the zinc and oxygen vacancies defects were confirmed by PL spectra. From the UV-Vis spectra, the band gap was estimated as 2.7 eV for pure and 2.9 eV for Mn doped ZnO NPs. The Mn doped ZnO NPs showed greater antibacterial effect than the pure ZnO NPs. The magnetization measurements for Mn doped ZnO samples under room temperature ferromagnetism (RTFM) showed the ferromagnetic phase that could originated from the interactions between Mn2+ ions and oxygen vacancies and the defects incorporated in the ZnO matrix.

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