Single-Crystalline Hollow Face-Centered-Cubic Cobalt Nanoparticles from Solid Face-Centered-Cubic Cobalt Oxide Nanoparticles

2008 ◽  
Vol 47 (49) ◽  
pp. 9504-9508 ◽  
Author(s):  
Ki Min Nam ◽  
Jae Ha Shim ◽  
Hosung Ki ◽  
Sang-Il Choi ◽  
Gaehang Lee ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Cobalt Nanoparticles ◽  
Oxide Nanoparticles ◽  
Face Centered Cubic ◽  
Single Crystalline ◽  
Cobalt Oxide Nanoparticles ◽  
Face Centered

Single-Crystalline Hollow Face-Centered-Cubic Cobalt Nanoparticles from Solid Face-Centered-Cubic Cobalt Oxide Nanoparticles

2008 ◽  
Vol 120 (49) ◽  
pp. 9646-9650 ◽  
Author(s):  
Ki Min Nam ◽  
Jae Ha Shim ◽  
Hosung Ki ◽  
Sang-Il Choi ◽  
Gaehang Lee ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Cobalt Nanoparticles ◽  
Oxide Nanoparticles ◽  
Face Centered Cubic ◽  
Single Crystalline ◽  
Cobalt Oxide Nanoparticles ◽  
Face Centered

scholarly journals Synthesis and Characterization of Cobalt Oxide Nanoparticles

2018 ◽  
Vol 4 (5) ◽  
pp. 475-477 ◽  
Author(s):  
K. Prema Latha ◽  
C. Prema ◽  
S. Meenakshi Sundar
Keyword(s):  
Crystallite Size ◽  
Cobalt Oxide ◽  
Visible Region ◽  
Synthesis And Characterization ◽  
Oxide Nanoparticles ◽  
Face Centered Cubic ◽  
Cobalt Oxide Nanoparticles ◽  
Vis Spectroscopy ◽  
Ft Ir

The present work reports the synthesis and characterization of cobalt oxide nanoparticles. Microwave oven method was used for synthesizing cobalt oxide nanoparticles. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, photoluminescence (PL) and scanning electron microscope (SEM). The prepared samples show poor crystalline nature so that the samples were calcined at 300 °C for 1 hr. The calcined samples were characterized for further changes in its morphology. XRD identifies the sample is in Co3O4 phase with face-centered cubic structure. Debye-Scherer formula was used to calculate the average crystallite size of the annealed sample and it was found to be 7 to 28 nm. In addition to crystallite size, specific surface area, dislocation density and microstrain are calculated using XRD. Williamson-Hall plot was used to calculate the size and strain. FT-IR spectrum shows two stretching bands at 660 and 550 cm−1 which confirm the functional group present in the cobalt oxide nanoparticles. In optical absorption studies, a blue shift in the energy band gap reveals the quantum confinement effect. Photoluminescence spectra shows emission peak in the visible region.

Characterization and Compatibility of High Oxygen Permeable Ophthalmic Biomaterial Containing Silane with Cobalt Oxide Nanoparticles

2020 ◽  
Vol 20 (11) ◽  
pp. 6954-6958
Author(s):  
Min-Jae Lee ◽  
A.-Young Sung
Keyword(s):  
Cobalt Oxide ◽  
Oxygen Permeability ◽  
Cobalt Nanoparticles ◽  
Cross Linking ◽  
Oxide Nanoparticles ◽  
Synergy Effect ◽  
Glycol Dimethacrylate ◽  
Cobalt Oxide Nanoparticles ◽  
Photo Polymerization ◽  
Oxide Nanoparticle

This research is conducted to analyze the compatibility of used monomers and produce the high functional hydrogel ophthalmic polymer containing silane and nanoparticles. Vinyltrimethoxysilane (VTMS) and cobalt oxide nanoparticles are used as additives for the basic combination of silicone monomer (Sil-H) and methyl methacrylate (MMA). And also, the materials are copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, photo polymerization initiator (2H2M) as the initiator. It is judged that the lenses of all combinations are optically excellent and thus have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic ophthalmic polymer are different in each case. Especially VTMS with cobalt oxide nanoparticle increases the oxygen permeability by the addition of cobalt nanoparticles. These materials are considered to make synergy effect each other, so it can be used in functional hydrogel ophthalmic lenses.

Green, efficient and large-scale synthesis of benzimidazoles, benzoxazoles and benzothiazoles derivatives using ligand-free cobalt-nanoparticles: as potential anti-estrogen breast cancer agents, and study of their interactions with estrogen receptor by molecular docking

RSC Advances ◽  
2015 ◽  
Vol 5 (130) ◽  
pp. 107822-107828 ◽  
Author(s):  
Abdol R. Hajipour ◽  
Zahra Khorsandi ◽  
Maryam Mortazavi ◽  
Hossein Farrokhpour
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Molecular Docking ◽  
Cobalt Oxide ◽  
Large Scale ◽  
Cobalt Nanoparticles ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Ligand Free ◽  
Large Scale Synthesis

A facile and high yielding method for the synthesis of 2-aryl benzoxazoles, benzimidazole and benzothiazoles is reported employing cobalt oxide nanoparticles.

Sustainable synthesis of cobalt and cobalt oxide nanoparticles and their catalytic and biomedical applications

2020 ◽  
Vol 22 (9) ◽  
pp. 2643-2661 ◽  
Author(s):  
Siavash Iravani ◽  
Rajender S. Varma
Keyword(s):  
Cobalt Oxide ◽  
Biomedical Applications ◽  
Cobalt Nanoparticles ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Recent Advances

Recent advances and essential challenges as well as catalytic and biomedical applications of cobalt oxide and cobalt nanoparticles are highlighted.

Synthesis of some Novel Imidazoles Catalyzed by Co3O4 Nanoparticles and Evaluation of their Antibacterial Activities

2018 ◽  
Vol 21 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Mohammad A. Ghasemzadeh ◽  
Mohammad H. Abdollahi-Basir ◽  
Zahra Elyasi
Keyword(s):  
Cobalt Oxide ◽  
Ammonium Acetate ◽  
Reaction Times ◽  
Antibacterial Activities ◽  
Primary Amines ◽  
Oxide Nanoparticles ◽  
Co3o4 Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Ft Ir ◽  
Tetrasubstituted Imidazoles

Aim and Objective: The multi-component condensation of benzil, primary amines, ammonium acetate and various aldehydes was efficiently catalyzed using cobalt oxide nanoparticles under ultrasonic irradiation. This approach describes an effective and facile method for the synthesis of some novel 1,2,4,5-tetrasubstituted imidazole derivatives with several advantages such as high yields and short reaction times and reusability of the catalyst. Moreover, the prepared heterocyclic compounds showed high antibacterial activity against some pathogenic strains. Materials and Method: The facile and efficient approaches for the preparation of Co3O4 nanoparticles were carried out by one step method. The synthesized heterogeneous nanocatalyst was characterized by spectroscopic analysis including EDX, FE-SEM, VSM, XRD and FT-IR analysis. The as-synthesized cobalt oxide nanoparticles showed paramagnetic behaviour in magnetic field. In addition, the catalytic influence of the nanocatalyst was examined in the one-pot reaction of primary amines, benzil, ammonium acetate and diverse aromatic aldehydes under ultrasonic irradiation. All of the 1,2,4,5-tetrasubstituted imidazoles were investigated and checked with m.p., 1H NMR, 13C NMR and FT-IR spectroscopy techniques. The antibacterial properties of the heterocycles were evaluated in vitro by the disk diffusion against pathogenic strains such as Escherichia coli (EC), Bacillus subtillis (BS), Staphylococcus aureus (SA), Salmonellatyphi (ST) and Shigella dysentrae (SD) species. Results: In this research cobalt oxide nanostructure was used as a robust and green catalyst in the some novel imidazoles. The average particle size measured from the FE-SEM image is found to be 20-30 nm which confirmed to the obtained results from XRD pattern. Various electron-donating and electron-withdrawing aryl aldehydes were efficiently reacted in the presence of Co3O4 nanoparticles. The role of the catalyst as a Lewis acid is promoting the reactions with the increase in the electrophilicity of the carbonyl and double band groups. To investigate the reusability of the catalyst, the model study was repeated using recovered cobalt oxide nanoparticles. The results showed that the nanocatalyst could be reused for five times with a minimal loss of its activity. Conclusion: We have developed an efficient and environmentally friendly method for the synthesis of some tetrasubstituted imidazoles via three-component reaction of benzil, primary amines, ammonium acetate and various aldehydes using Co3O4 NPs. The present approach suggests different benefits such as: excellent yields, short reaction times, simple workup procedure and recyclability of the magnetic nanocatalyst. The prepared 1,2,4,5-tetrasubstituted imidazoles revealed high antibacterial activities and can be useful in many biomedical applications.

Green Synthesis of Cobalt Oxide Nanoparticles by a Starch-Assisted Method

2019 ◽  
Vol 9 (3) ◽  
pp. 362-370 ◽  
Author(s):  
D. Vaya ◽  
Meena ◽  
B.K. Das
Keyword(s):  
Photocatalytic Activity ◽  
Cobalt Oxide ◽  
Sol Gel ◽  
Complex Nature ◽  
Oxide Nanoparticles ◽  
Capping Agent ◽  
Chemical Route ◽  
Gel Method ◽  
Sol Gel Method ◽  
Cobalt Oxide Nanoparticles

Background: The properties of the material are altered when material size shifted towards nano-regime. This feature could be used for wastewater treatment process using model pollutant such as dyes. Recently, nanoparticles are synthesized by a green chemical route using different capping agents. This is the reason we adopt starch as green capping agent along with sol-gel method. Objective: To synthesize cobalt oxide nanoparticles by green chemical route and utilized it in degradation of dyes. Methods: Synthesis of cobalt oxide nanoparticles by sol-gel method using starch as a capping agent. The characteristics of surface modifications were investigated by UV-VIS, TEM, SEM, XRD and FTIR techniques. Results: Cobalt oxide nanoparticles synthesized and inhibited photocatalytic activity. Conclusion: Deactivation of photocatalytic activity due to complex nature of starch. This property can be used elsewhere as in light shielding applications to coat and protect surfaces in order to keep them cool and safe from damage as in the painting of vehicles, roofs, buildings, water tanks, etc.

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