scholarly journals Optimisation of Cobalt Oxide Nanoparticles Synthesis as Bactericidal Agents

2019 ◽  
Vol 7 (17) ◽  
pp. 2757-2762 ◽  
Author(s):  
Hedaiat Moradpoor ◽  
Mohsen Safaei ◽  
Farzad Rezaei ◽  
Amin Golshah ◽  
Ladan Jamshidy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cobalt Oxide ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Bactericidal Effect ◽  
Cobalt Nitrate ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Stirring Time ◽  
The Fourier Transform

AIM: With the increased bacterial resistance and the resulting problems in recent years, it seems necessary to find new biocompatible compounds to confront this problem. This research was conducted to optimise the synthesis of cobalt oxide nanoparticles with the highest antibacterial activity. METHODS: In the present study, 9 experiments were designed using the Taguchi method. The effect of three factors of cobalt nitrate, KOH and the stirring time in the synthesis of cobalt oxide nanoparticles with the highest antibacterial activity was investigated. The bactericidal effect of synthesised nanoparticles was evaluated using the colony-forming unit (CFU) and disk diffusion methods. The characteristics of nanoparticles were studied using the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and the scanning electron microscopy (SEM). RESULTS: The results indicated that all three evaluated factors were effective on the antibacterial properties of the synthesised nanoparticles. The best antibacterial activity of cobalt oxide nanoparticles was observed in experiment 9 (cobalt nitrate 0.6 M, KOH 2M and stirring time 60 min). The study of nanoparticles synthesised by FTIR, XRD, and SEM confirmed the formation of cobalt oxide nanoparticles with size (24 nm) and a proper structure (spinel structure). CONCLUSION: Due to the optimal antibacterial properties of the synthesised cobalt oxide nanoparticles, they can be used in the fabrication of dental and medical equipment with antibacterial properties.

Synthesis and characterization of nano sized cobalt oxide by precipitation method

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Pavithra D ◽  
Sujatha K ◽  
Sudha A P
Keyword(s):  
Cobalt Oxide ◽  
Ammonium Oxalate ◽  
Cobalt Nitrate ◽  
Morphological Properties ◽  
Precipitation Method ◽  
Oxide Nanoparticles ◽  
Average Crystalline Size ◽  
Co3o4 Nanoparticles ◽  
X Ray ◽  
Cobalt Oxide Nanoparticles

In the present work, cobalt oxide nanoparticles were prepared by using precipitation method. The cobalt nitrate [Co (No3)2] and ammonium oxalate [C2H8N2O4] were used as precursors for the synthesis of cobalt oxide nanoparticles and the resultant product was Calcinated at 400˚C for 2 hrs. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDAX) to analyze the structural and morphological properties. The XRD pattern of the synthesized cobalt oxide nanoparticles exhibits cubic structure with the average crystalline size of 8.06 nm. The functional groups of the synthesized nanoparticles were confirmed by using FTIR spectrum (400 to 4000 cm-1). In the synthesized sample and its purity were confirmed from EDAX spectrum. The surface morphology of the synthesized Co3O4 nanoparticles shows spherical morphology. The optical properties of the synthesized cobalt oxide nanoparticles were investigated by photoluminescence spectrum which shows a minor emission at around 440 nm.

scholarly journals Multiwalled Carbon Nanotubes Decorated with Cobalt Oxide Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
D. G. Larrude ◽  
P. Ayala ◽  
M. E. H. Maia da Costa ◽  
F. L. Freire
Keyword(s):  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Cobalt Nitrate ◽  
Oxide Nanoparticles ◽  
Nitrate Hexahydrate ◽  
Multiwalled Carbon ◽  
Cobalt Oxide Nanoparticles ◽  
Electron Microscopy Analysis ◽  
Average Size

Multiwalled carbon nanotubes (MWCNTs) synthesized by spray pyrolysis were decorated with cobalt oxide nanoparticles using a simple synthesis route. This wet chemistry method yielded nanoparticles randomly anchored to the surface of the nanotubes by decomposition of cobalt nitrate hexahydrate diluted in acetone. Electron microscopy analysis indicated that dispersed particles were formed on the MWCNTs walls. The average size increased with the increasing concentration of cobalt nitrate in acetone in the precursor mixture. TEM images indicated that nanoparticles were strongly attached to the tube walls. The Raman spectroscopy results suggested that the MWCNT structure was slightly damaged after the nanoparticle growth.

Spinel-Type Cobalt Oxide Nanoparticles: Synthesis, Characterization and Antibacterial Properties

2020 ◽  
Vol 12 (7) ◽  
pp. 859-863
Author(s):  
S. Ambika ◽  
S. Gopinath ◽  
K. Sivakumar ◽  
K. Saravanan
Keyword(s):  
Electron Microscopy ◽  
Cobalt Oxide ◽  
Average Particle Size ◽  
Antibacterial Properties ◽  
Synthesis Temperature ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
Spinel Type ◽  
Cobalt Oxide Nanoparticles ◽  
The Impact

A series of cobalt oxide nanoparticles (sample A (300 °C), sample B (400 °C) and sample C (500 °C)) are synthesized in a starch medium by the hydrothermal method followed by annealing. The structural, morphological, and magnetic, of these cobalt oxide nanoparticles, become characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) correspondingly. Furthermore, it can be seen that the increase in the synthesis temperature results in a substantial increase in the average particle size. The impact of synthesis temperature in relation to morphology (size and shape) and magnetic properties of cobalt oxide nanoparticles has been investigated. Besides, the antibacterial and catalytic activity of these nanoparticles are examined. A systematic analysis is presented on the influence of parameters of synthesis on the formation and structural properties of cobalt oxide nanoparticles. We expect in which this topic will give many valuable ideas for the metal oxide nanomaterials development, synthesis, as well as applications.

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.

scholarly journals Correction: An anionic and cationic surfactant-assisted hydrothermal synthesis of cobalt oxide nanoparticles as the active electrode material for supercapacitors

2021 ◽  
Author(s):  
R. R. Samal ◽  
Aneeya K. Samantara ◽  
S. Mahalik ◽  
J. N. Behera ◽  
B. Dash ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Cobalt Oxide ◽  
Cationic Surfactant ◽  
Electrode Material ◽  
Oxide Nanoparticles ◽  
Active Electrode ◽  
Cobalt Oxide Nanoparticles ◽  
Surfactant Assisted

Correction for ‘An anionic and cationic surfactant-assisted hydrothermal synthesis of cobalt oxide nanoparticles as the active electrode material for supercapacitors’ by R. R. Samal et al., New J. Chem., 2021, 45, 2795–2803; DOI: 10.1039/D0NJ05088A.

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