scholarly journals Microbial and Plant Assisted Synthesis of Cobalt Oxide Nanoparticles and Their Antimicrobial Activities

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1607
Author(s):  
Nadia Mubraiz ◽  
Asghari Bano ◽  
Tariq Mahmood ◽  
Naeem Khan
Keyword(s):  
Particle Size ◽  
Bacillus Subtilis ◽  
Fusarium Oxysporum ◽  
Cobalt Oxide ◽  
Bacterial Strain ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
Co3o4 Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Wide Range

The development of sustainable, ecofriendly, and cost-effective methods for the synthesis of nanomaterials is an important aspect of nanotechnology these days. The present study was aimed at synthesizing cobalt oxide (Co3O4) nanoparticles by using plant extracts of Aerva javanica, bacterial isolates from rhizospheric soil of Potentilla atrosanguinea, Swertia petiolata, Senecio chrysanthemoides, and from fungus Fusarium oxysporum. X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM) techniques were used in the characterization of the synthesized nanoparticles. The bacterial strain, Bacillus subtilis, isolated from rhizosphere of Potentilla atrosanguinea (N1C1), Fusarium oxysporum, methanolic and aqueous extracts of Aerva javanica reduced the cobalt salts to cobalt oxide nanoparticles. The nanoparticles, synthesized from bacterial isolate N1C1 (Bacillus subtilis) and from Fusarium oxysporum had average particle size of 31.2 nm and 33.4 nm, respectively, whereas, the particle size of Aerva javanica was higher (39.2 nm) and all the nanoparticles were poly shaped. The nanoparticles synthesized from methanolic extract of Aerva javanica, bacterial strain (N1C1) and fungi Fusarium oxysporum showed better performance against Bacillus subtilis and P. aeruginosa, the bactericidal activity was higher against Gram-positive bacterial strains. Methanolic extracts of leaf and flower have shown a wide range of phytochemicals and higher antibacterial activity, and among all strains, Pseudomonas aeruginosa and Bacillus subtilis susceptibility was greater to extracts.

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.

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 Wet Synthesis of Monodisperse Cobalt Oxide Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Taimur Athar ◽  
Abdul Hakeem ◽  
Neha Topnani ◽  
Ameed Hashmi
Keyword(s):  
Particle Size ◽  
Cobalt Oxide ◽  
Morphological Characterization ◽  
Oxide Nanoparticles ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Cobalt Oxide Nanoparticles ◽  
Ir Studies ◽  
Ft Ir ◽  
Wet Synthesis

Ultrafine and monodispersable colloidal cobalt oxide nanoparticles were successfully synthesized quantitatively via soft chemical approach with controlled particle size and microstructural properties for their use in technological applications. The particle size, shape, and other microstructural properties are directly influenced by their reaction conditions. The FT-IR studies give information for phase purity, and ultraviolet absorption spectroscopy helps to study the optical properties. Thermal analysis gives the information about thermal stability. With the help of X-ray diffraction pattern, the size of the particle was calculated. An electron microscope studies help in morphological characterization, and Brunauer-Emmett-Teller method gives information about surface area. Cobalt oxide nanoparticle tends to orient itself with its narrow size distribution having a crystal size around 50 nm.

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.

Adsorption of microbial esterases on Bacillus subtilis-templated cobalt oxide nanoparticles

2014 ◽  
Vol 65 ◽  
pp. 188-192 ◽  
Author(s):  
Eunjin Jang ◽  
Bum Han Ryu ◽  
Hyun-Woo Shim ◽  
Hansol Ju ◽  
Dong-Wan Kim ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Cobalt Oxide ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles

scholarly journals Synthesis of nanocellulose/cobalt oxide composite for efficient degradation of Rhodamine B by activation of peroxymonosulfate

2019 ◽  
Vol 10 (1) ◽  
pp. 19-25
Author(s):  
Faouzia Khili ◽  
Amel Dakhlaoui Omrani
Keyword(s):  
Cobalt Oxide ◽  
Rhodamine B ◽  
Cellulose Nanocrystals ◽  
Oxide Nanoparticles ◽  
Co3o4 Nanoparticles ◽  
Electron Microscopic ◽  
Visible Absorption ◽  
Cobalt Oxide Nanoparticles ◽  
Transmission Electron ◽  
Short Period

In recent years, nanofibrous materials derived from biopolymers have attracted more interest due to their numerous applications. In our study, a simple composite of cellulose nanocrystals, and cobalt oxide nanoparticles was elaborated using sodium borohydride as a chemical reducer. It has been shown that Co3O4 nanoparticles were grown on the surface of cellulose nanocrystals. An important quantity of cobalt oxide nanoparticles was detected using ICP-OES (13.5 g contained in 100 mg of the composite). The size, the morphology and the thermal stability of the composite and the obtained nanoparticles were studied using X-ray powder diffraction, Fourier-transform infrared spectroscopy, Ultraviolet-Visible spectrophotometry, Scanning electron microscopic and Transmission electron microscopic. Our obtained material was used for the degradation of Rhodamine B and it was succeeded in degradation of Rhodamine B within very short period of time (16 min). The catalytic degradation of Rhodamine B was investigated and analyzed with UV-Visible absorption spectra.

Continuous hydrothermal crystallization of α–Fe2O3 and Co3O4 nanoparticles

2003 ◽  
Vol 18 (2) ◽  
pp. 415-422 ◽  
Author(s):  
Yalin Hao ◽  
Amyn S. Teja
Keyword(s):  
Particle Size ◽  
Sodium Hydroxide ◽  
Cobalt Oxide ◽  
Residence Time ◽  
Average Particle Size ◽  
Cobalt Nitrate ◽  
Metal Nitrate ◽  
Average Particle ◽  
Co3o4 Nanoparticles ◽  
Feed Concentration

Iron oxide (α–Fe2O3) and cobalt oxide (Co3O4) were produced via precipitation reactions carried out in a continuous hydrothermal apparatus. The resulting particles were nanometer-sized because of the high supersaturations generated when metal nitrate solutions are combined with sodium hydroxide or with hot, compressed water. The average particle size increased with the metal nitrate feed concentration and with residence time. A logarithmic relationship was obtained between the particle size and feed concentration and between particle size and residence time in the apparatus. The production of nanoparticles with narrow size distribution was shown to require low metal nitrate feed concentrations and short residence times. In the range of temperatures studied in this work, temperature apparently had no effect on the size except when cobalt nitrate was contacted with supercritical water in the absence of sodium hydroxide. In this case, large cobalt oxide particles were obtained when the temperature was above the critical temperature of water.

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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