Investigations on microstructure, optical, magnetic, photocatalytic, and dielectric behaviours of pure and Co-doped ZnO NPs

2020 ◽  
Vol 31 (8) ◽  
pp. 6360-6371 ◽  
Author(s):  
M. A. Majeed Khan ◽  
Rahul Siwach ◽  
Sushil Kumar ◽  
Maqusood Ahmed ◽  
Jahangeer Ahmed
Keyword(s):  
Zno Nps ◽  
Doped Zno ◽  
Co Doped

scholarly journals Hydrogen Sensing Properties of Co-Doped ZnO Nanoparticles

Chemosensors ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 61 ◽  
Author(s):  
Fatemeh Moosavi ◽  
Mohammad Ebrahim Bahrololoom ◽  
Ramin Kamjou ◽  
Ali Mirzaei ◽  
Salvatore Gianluca Leonardi ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
High Performance ◽  
Gas Sensing ◽  
Sol Gel ◽  
Breath Hydrogen ◽  
Zno Nps ◽  
Sensing Properties ◽  
Co Doping ◽  
Doped Zno ◽  
Co Doped

In this study, the gas sensing properties of Co-doped ZnO nanoparticles (Co-ZnO NPs) synthesized via a simple sol-gel method are reported. The microstructure and morphology of the synthesized Co-ZnO NPs were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Co-ZnO NPs were then used for developing a conductometric gas sensor for the detection, at mild temperature, of low concentration of hydrogen (H2) in air. To evaluate the selectivity of the sensor, the sensing behavior toward some VOCs such as ethanol and acetone, which represent the most important interferents for breath hydrogen analysis, was also investigated in detail. Results reported demonstrated better selectivity toward hydrogen of the Co-ZnO NPs sensor when compared to pure ZnO. The main factors contributing to this behavior, i.e., the transition from n-type behavior of pristine ZnO to p-type behavior upon Co-doping, the modification of oxygen vacancies and acid-base characteristics have been considered. Hence, this study highlights the importance of Co doping of ZnO to realize a high performance breath hydrogen sensor.

scholarly journals Facile Green Synthesis of LaCe Co-Doped ZnO Nanoparticles and Their Structural, Optical and Antibacterial Properties

2018 ◽  
Vol 4 (5) ◽  
pp. 552-554
Author(s):  
M. Karthikeyan ◽  
A. Jafar Ahamed ◽  
P. Vijaya Kumar
Keyword(s):  
Green Synthesis ◽  
Zno Nanoparticles ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Inert Gases ◽  
Diffusion Method ◽  
Zno Nps ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Co Doped

This present work describes the synthesis of LaCe co-doped zinc oxide (ZnO) nanoparticles (NPs) prepared by green method using Gymnema sylvestre (G. sylvestre) leaves as reducing as well as capping agent. Green synthesis method avoids inert gases, high pressure, laser radiation, high temperature, toxic chemicals etc. as compared to conventional method like sol-gel technique method, laser ablation method, solvothermal method, inert gas condensation method and chemical reduction method. The synthesized LaCe co-doped ZnO NPs was characterized by X-Ray diffraction (XRD), field emission scanning electron microscopy (FESEM), elemental analysis (EADX), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy and photoluminescence (PL). The LaCe co-doped ZnO NPs was tested against clinical pathogens such as gram positive G+ (Staphylococcus aureus and Streptococcus pneumoniae) and gram negative G- (Klebsiella pneumoniae, Shigella sydenteriae, Escherichia coli, Pseudomonas aeruginosa and Protus vulgaris) bacterial strains using agar well diffusion method.

scholarly journals Enhanced Photocatalytic Activity of ZnO Nanoparticles Co-Doped With Rare Earth Elements (Nd and Sm) Under UV Light Illumination

2021 ◽  
Author(s):  
P. Baskaran ◽  
A. Pramothkumar ◽  
Mani P
Keyword(s):  
Photocatalytic Activity ◽  
Zno Nanoparticles ◽  
Dye Degradation ◽  
Uv Light ◽  
Present Report ◽  
Precipitation Method ◽  
Light Illumination ◽  
Zno Nps ◽  
Doped Zno ◽  
Co Doped

Abstract In the present report, synthesis of pure, Nd-doped (1 wt.%) and Nd/Sm (1 wt.%) co-doped Zinc Oxide (ZnO) Nanoparticles (NPs) by using simple co-precipitation method. PXRD pattern of all the synthesized samples exposes the hexagonal crystal structure of ZnO NPs without any impurity. The various functional groups presented in the synthesized samples were analyzed by FT-IR studies. From UV-Vis DRS spectra, the band gap was found to be 2.81 eV, 2.90 and 3.10 eV respectively for pure, Nd-doped and Nd-Sm co-doped ZnO NPs. PL spectrum displays the broad emission at 393and 450 nm for all the synthesized samples. The agglomeration of flower-like morphology of pure ZnO NPs, flake-like structure of Nd-doped and rod-like morphology of Nd/Sm co-doped ZnO NPs were examined by SEM. Photocatalytic activity of the prepared samples for dye degradation of Acid Orange 7 (AO-7) and Acid Red 13 (AR-13) was studied under UV light. The result revealed that, the Nd/Sm co-doped ZnO NPs found to have efficient degradation candidate materials.

Morphological, structural, and optical properties of Co-doped ZnO NPs prepared by precipitation method

2019 ◽  
Vol 20 (5) ◽  
pp. 518-521
Author(s):  
S. Iwan ◽  
Riser Fahdiran ◽  
Erfan Handoko ◽  
Esmar Budi ◽  
Anggara Budi Susila ◽  
...  
Keyword(s):  
Optical Properties ◽  
Precipitation Method ◽  
Structural And Optical Properties ◽  
Zno Nps ◽  
Doped Zno ◽  
Co Doped

ROOM TEMPERATURE FERROMAGNETISM IN Co-DOPED ZnO NANOPARTICLES: MILLING TIME DEPENDENCE AND ANNEALING EFFECT

2011 ◽  
Vol 10 (01n02) ◽  
pp. 307-311 ◽  
Author(s):  
BAPPADITYA PAL ◽  
P. K. GIRI
Keyword(s):  
Zno Nanoparticles ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Magnetic Impurities ◽  
Zno Nps ◽  
Small Magnitude ◽  
Doped Zno ◽  
Co Doped

We report on the occurrence of room temperature ferromagnetism in Co -doped ZnO nanoparticles (NPs). Doping is performed by ball milling of 3 wt% of Co mixed with ZnO nanopowders (commercial) for durations of 2–8 h. X-ray diffraction data and high-resolution transmission electron microscopy (HRTEM) confirm the absence of metallic Co clusters or any other phase different from würtzite-type ZnO . The magnetization (M–H curve) measured at room temperature exhibits the clear ferromagnetic characteristic with saturation magnetization (Ms) and coercive field (Hc) of the order of 3–4 emu/g and 225 Oe, respectively. Post-growth annealing at 250°C results in an increase of Ms by a small magnitude, while annealing at 500°C results in reduction of Ms. UV–visible absorption spectra show small redshift in the absorption peaks in the Co -doped ZnO NPs due to the incorporation of Co atoms in ZnO lattice. Room temperature photoluminescence studies show enhanced near-band-edge emission at 378 nm in the doped NPs as compared to the undoped NPs indicating low density of defects in the doped ZnO crystals. Contribution of intrinsic defects and magnetic impurities in the observed ferromagnetism is discussed.

Influence of N Dopant on the Electric and Magnetic Properties of Co Doped ZnO Thin Films

2010 ◽  
Vol 25 (7) ◽  
pp. 711-716 ◽  
Author(s):  
Xue-Tao WANG ◽  
Li-Ping ZHU ◽  
Zhi-Gao YE ◽  
Zhi-Zhen YE ◽  
Bing-Hui ZHAO
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Zno Thin Films ◽  
Doped Zno ◽  
Co Doped

Photoluminescence and Magnetic Properties of Undoped and (Mn, Co) co-doped ZnO Nanoparticles

2020 ◽  
Vol 16 (4) ◽  
pp. 655-666
Author(s):  
Mona Rekaby
Keyword(s):  
Magnetic Properties ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Structural Defects ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Antiferromagnetic Ordering ◽  
Doped Zno ◽  
Co Doped

Objective: The influence of Manganese (Mn2+) and Cobalt (Co2+) ions doping on the optical and magnetic properties of ZnO nanoparticles was studied. Methods: Nanoparticle samples of type ZnO, Zn0.97Mn0.03O, Zn0.96Mn0.03Co0.01O, Zn0.95Mn0.03 Co0.02O, Zn0.93Mn0.03Co0.04O, and Zn0.91Mn0.03Co0.06O were synthesized using the wet chemical coprecipitation method. Results: X-ray powder diffraction (XRD) patterns revealed that the prepared samples exhibited a single phase of hexagonal wurtzite structure without any existence of secondary phases. Transmission electron microscope (TEM) images clarified that Co doping at high concentrations has the ability to alter the morphologies of the samples from spherical shaped nanoparticles (NPS) to nanorods (NRs) shaped particles. The different vibrational modes of the prepared samples were analyzed through Fourier transform infrared (FTIR) measurements. The optical characteristics and structural defects of the samples were studied through Photoluminescence (PL) spectroscopy. PL results clarified that Mn2+ and Co2+ doping quenched the recombination of electron-hole pairs and enhanced the number of point defects relative to the undoped ZnO sample. Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM). (Mn, Co) co-doped ZnO samples exhibited a ferromagnetic behavior coupled with paramagnetic and weak diamagnetic contributions. Conclusion: Mn2+ and Co2+ doping enhanced the room temperature Ferromagnetic (RTFM) behavior of ZnO. In addition, the signature for antiferromagnetic ordering between the Co ions was revealed. Moreover, a strong correlation between the magnetic and optical behavior of the (Mn, Co) co-doped ZnO was analyzed.

Optimizing physical properties of Co-doped ZnO nanoparticles: Controlling oxygen vacancy and carrier concentration

Vacuum ◽  
2021 ◽  
pp. 110488
Author(s):  
Huying Yan ◽  
Jian Xue ◽  
Wenjing Chen ◽  
Jialing Tang ◽  
Ling zhong ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Physical Properties ◽  
Carrier Concentration ◽  
Zno Nanoparticles ◽  
Doped Zno ◽  
Co Doped

Transport mechanisms in Co-doped ZnO (ZCO) and H-irradiated ZCO polycrystalline thin films

2021 ◽  
Vol 23 (3) ◽  
pp. 2368-2376
Author(s):  
A. Di Trolio ◽  
A. Amore Bonapasta ◽  
C. Barone ◽  
A. Leo ◽  
G. Carapella ◽  
...  
Keyword(s):  
Thin Films ◽  
Opposite Effect ◽  
Transport Mechanisms ◽  
Co Doping ◽  
Polycrystalline Thin Films ◽  
Doped Zno ◽  
Co Doped

Co doping increases the ZnO resistivity (ρ) at high T (HT), whereas it has an opposite effect at low T (LT). H balances the Co effects by neutralizing the ρ increase at HT and strengthening its decrease at LT.

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