Protective Agent-Free Synthesis of Colloidal Cobalt Nanoparticles

Balela, Mary Donnabelle L.; Lockman, Zainovia; Aziz, Azizan; Matsubara, Eiichiro; Amorsolo, Alberto V.

doi:10.1063/1.3377794

Cited by 3 publications

(4 citation statements)

References 25 publications

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“…The resulting yellow solution was equilibrated at ambient temperature and vacuum-evaporated. The products were separated by TLC (silica gel, aluminum oxide sheets Si 60 F 254 , 5 × 10 cm, EMD Chemicals, Gibbstown, NJ) using hexane-ethyl acetate (80:20 v/v). , Yield, 75%. The initial compounds moved with the solvent front; the product observed under UV ( R f ≈ 0.5) was separated and dissolved in 250 μL of CD 3 OD.…”

Section: Methodsmentioning

confidence: 99%

Reactive Silver and Cobalt Nanoparticles Modified with Fatty Acid Ligands Functionalized by Imidazole Derivatives

et al. 2010

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Novel nucleophilic ligands were synthesized from oleic acid conjugated with 2-mercaptoimidazole via a UV-initiated thiol−ene reaction, and by a condensation of trans-9,10-epoxystearic acid with 4(5)-imidazoledithiocarboxylic acid. Nanoparticles (NPs) with 10−100 nm Ag(0) or Co(0) cores were obtained by reduction of Ag+ or Co2+ by borohydride in N,N-dimethylformamide or aqueous solutions respectively. The NPs capped with oleic acid or 9,10-epoxystearic acids were further covalently bound to 2-mercaptoimidazole or 4(5)-imidazoledithiocarboxylic acid. The ligands and NPs functionalized with nucleophilic imidazole moieties enabled facile hydrolysis of paraoxon (O,O-diethyl O-(p-nitrophenyl) phosphate) by NPs in their aqueous media. The NPs acted as recoverable semiheterogeneous catalysts. The paraoxon hydrolysis was accelerated 10- to 50-fold by the formation of complexes between the imidazole-containing ligands or NPs with Co2+.

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Section: Methodsmentioning

confidence: 99%

Reactive Silver and Cobalt Nanoparticles Modified with Fatty Acid Ligands Functionalized by Imidazole Derivatives

et al. 2010

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“…Thus, a proper choice of the polyol is important, having the reducing potential suitable to carry out the reduction of the cobalt precursor. It has been shown that increasing the temperature and pH of the reaction mixture increase the rate of the overall reaction [253] . While the reduction of metal salts with borohydride is very fast, occurring at room temperature and producing relatively small NPs, the reduction using polyol is usually slow.…”

Section: Preparation Of Cobalt Nanoparticlesmentioning

confidence: 99%

“…Balela and coworkers reported a facile low‐temperature synthesis of colloidal Co NPs by reduction of CoCl 2 ⋅ 6H 2 O in EG [253] . The obtained colloidal particles were spherical and monodispersed with an average diameter of 2–7 nm.…”

Section: Preparation Of Cobalt Nanoparticlesmentioning

confidence: 99%

Preparation of Cobalt Nanoparticles

et al. 2021

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The development of modern chemistry is currently proceeding in several priority areas including investigations focused on the synthesis, stabilisation, and application of transition metal nanoparticles (NPs), which are widely used in physical, chemical, engineering, and biomedical processes. A special place among known transition metal NPs is occupied by cobalt nanoparticles, since they are used for highly important targets, such as creation of new catalysts, magnetic devices, composites, or carriers for drug delivery. The selective preparation of NPs is a difficult task that requires special conditions and has some limitations. In this minireview, we summarise the most successful and most efficient methods for obtaining Co NPs, including chemical and physical aspects of their preparation.

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“…It should be noted that due to the instrumental limits of the HRTEM approach, we were able to detect the growth process of the nanoparticles with a minimum diameter of 1.5 nm for Ni and Co, instead of detecting the nucleation process . Nevertheless, these are in a good agreement with the recently reported minimal diameters of ∼1 nm Ni and ∼2 nm Co , nanocrystallites. Moreover, we have revealed that the growth of metal nanoparticles (Ni or Co) inside the organic matrix is accompanied by (i) a constant lattice parameters (within the metrical error, Figure S21A), (ii) constant lattice orientation in space (Figure S21B–E), and (iii) the constant spatial position of the nanoparticle over time (Figure S9).…”

Section: Resultsmentioning

confidence: 99%

Insights into Solid-To-Solid Transformation of MOF Amorphous Phases

et al. 2022

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Metal–organic frameworks (MOFs) have been recently explored as crystalline solids for conversion into amorphous phases demonstrating non-specific mechanical, catalytic, and optical properties. The real-time control of such structural transformations and their outcomes still remain a challenge. Here, we use in situ high-resolution transmission electron microscopy with 0.01 s time resolution to explore non-thermal (electron induced) amorphization of a MOF single crystal, followed by transformation into an amorphous nanomaterial. By comparing a series of M-BTC (M: Fe3+, Co3+, Co2+, Ni2+, and Cu2+; BTC: 1,3,5-benzentricarboxylic acid), we demonstrate that the topology of a metal cluster of the parent MOFs determines the rate of formation and the chemistry of the resulting phases containing an intact ligand and metal or metal oxide nanoparticles. Confocal Raman and photoluminescence spectroscopies further confirm the integrity of the BTC ligand and coordination bond breaking, while high-resolution imaging with chemical and structural analysis over time allows for tracking the dynamics of solid-to-solid transformations. The revealed relationship between the initial and resulting structures and the stability of the obtained phase and its photoluminescence over time contribute to the design of new amorphous MOF-based optical nanomaterials.

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Protective Agent-Free Synthesis of Colloidal Cobalt Nanoparticles

Cited by 3 publications

References 25 publications

Reactive Silver and Cobalt Nanoparticles Modified with Fatty Acid Ligands Functionalized by Imidazole Derivatives

Reactive Silver and Cobalt Nanoparticles Modified with Fatty Acid Ligands Functionalized by Imidazole Derivatives

Preparation of Cobalt Nanoparticles

Insights into Solid-To-Solid Transformation of MOF Amorphous Phases

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