Ag-deposited silica-coated Fe3O4 magnetic nanoparticles catalyzed reduction of p-nitrophenol

Du, Xiaoyan; Zhu, Jie; Sun, Lijuan; An, Songsong

doi:10.1016/j.apsusc.2011.10.122

Cited by 232 publications

(114 citation statements)

References 41 publications

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“…The gradual decrease in the characteristic peak of 4-NP was due to the decrease in concentration of 4-NP as a result of the conversion of 4-NP to 4-AP on the surface of Ni and Co nanoparticles inside the microgels. This catalytic effect is due to the electron relay from electron donor BH 4 -to acceptor 4-NP via the nanoparticles and proceeds the reduction; thus the color of the reaction mixture changed from bright yellow to colorless (47). Although the reduction of 4-NP to 4-AP in the presence of aqueous solution of NaBH 4 is thermodynamically favorable, the presence of a large kinetic barrier due to the large potential difference between electron donor and acceptor species suppresses the feasibility of this reaction.…”

Section: Catalytic Activity Of Hybrid Microgelsmentioning

confidence: 99%

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

et al. 2014

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Abstract:In this research work, multi-responsive poly(Nisopropylacrylamide-co-methacrylic acid) copolymer microgels were synthesized via emulsion polymerization in aqueous medium. Then, nickel and cobalt nanoparticles were fabricated within these microgels by in situ reduction of metal ions using sodium borohydride (NaBH 4 ) as a reducing agent. Fourier transform infrared spectroscopy was used to characterize these microgels. The pH sensitivity of these copolymer microgels was studied using dynamic light scattering technique (DLS). DLS studies revealed that the hydrodynamic radius of these microgels increased with the increase in pH of the medium at 25°C. The catalytic activity of hybrid microgels for the reduction of p-nitrophenol (4-NP) to p-aminophenol (4-AP) was investigated by UV-visible spectrophotometery. The value of apparent rate constant of reaction was found to change linearly with catalyst dosage. The nickel-based hybrid system was found to be five times more efficient as a catalyst compared to the cobalt-based hybrid system for the reduction of 4-NP to 4-AP in aqueous medium.

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Section: Catalytic Activity Of Hybrid Microgelsmentioning

confidence: 99%

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

et al. 2014

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“…As the concentration of KBH4 largely exceeds the concentration of 4-NP, it can be considered as a constant during the reaction, and therefore the reduction can be regarded as pseudo-first-order reaction. Since the absorbance of 4-NP is proportional to its concentration in the medium, the ratio of At (t=t) to A0 (t=0) must be equal to the concentration ratio Ct/C0 of 4-NP [24]. The kinetic equation for the reduction can be written as Equation (1).…”

Section: Catalytic Activitymentioning

confidence: 99%

Preparation of Nitrogen-Doped Carbon Materials from Monosodium Glutamate and Application in Reduction of p-Nitrophenol

Cai

Zhou

et al. 2017

Bull. Chem. React. Eng. Catal.

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Nitrogen-doped carbons (NCs) as supports for metal catalysts used in heterogeneous reactions are increasingly being investigated. In this work, NCs were prepared from monosodium glutamate (MSG) by direct carbonization, which were used as supporters to prepare Bi/NC catalysts. The Bi/NC catalysts were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and nitrogen adsorption isotherm. The results indicate that nitrogen was doped in the formation of pyridinic N, pyrrolic N, and graphitic N. The NCs possess high surface area (~652 m 2 /g) and uniform mesopore size (~2.11 nm). Bismuth nanoparticles (NPs) dispersed uniformly in NC with diameter of 10-20 nm. The catalytic performances were investigated using the reduction of 4-nitrophenol (4-NP) with excess potassium borohydride as a model reaction, the results indicating that the Bi/NC catalysts have higher activity and better reusability than the Bi/AC catalyst. Under the following conditions: 100 mL of 4-NP (2 mM), 0.03 g of 3%Bi/NC, n(KBH4) : n(4-NP) = 40:1, and at room temperature, the rate constant k can reach 0.31 min -1 .

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“…Afterwards, a magnet was placed near the rim of the plate [16]. After passing of 2 min, the nanoparticles assembled completely on the rim of the plate and the suspension became transparent (Fig.…”

Section: Determination Of Synthesized Nanoparticles' Qualitiesmentioning

confidence: 99%

Aflatoxin M1 detoxification from infected milk using Fe3O4 nanoparticles attached to specific aptamer

et al. 2017

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Aflatoxins are a kind of mycotoxins that are mostly produced by a group of molds such as Aspergillus flavus and Aspergillus parasiticus. The studies on different parts of Iran showed that AFM 1 infection of milk is higher than European Union's standard. In this study, the specific aptamer with the carboxylic group at the end of 5′ and Fe 3 O 4 nanoparticles with amine groups was synthesized. Morphological and structural qualities of Fe 3 O 4 were determined by the Fourier-transform infrared spectrograph (FTIR), dynamic light scattering, scanning electron microscope, and X-ray diffraction devices. The specificity of the aptamer to AFM 1 was investigated in adjacent of AFM 1 and aflatoxin B 1 . Then, aptamers were attached to nanoparticles to improve synthetic qualities and to ease of its detachment. The attachment was approved by FTIR method. The complex (Fe 3 O 4 -APT) was then added to infected milk and after the proper time was detached from the milk using a magnet. The remained amount of AFM 1 was attained in milk using high-performance liquid chromatography. Our result showed that this method for aflatoxin detoxification is much more effective than conventional methods based on recognition of AFM 1 and their concentration in infected milk. This method is more applicable, faster, and cheaper highlighting its application in milk factories. Graphical abstractKeywords Aflatoxin · Aptamer · Fe 3 O 4 nanoparticle · Detoxification · Mycotoxin

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Ag-deposited silica-coated Fe3O4 magnetic nanoparticles catalyzed reduction of p-nitrophenol

Cited by 232 publications

References 41 publications

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

Preparation of Nitrogen-Doped Carbon Materials from Monosodium Glutamate and Application in Reduction of p-Nitrophenol

Aflatoxin M1 detoxification from infected milk using Fe3O4 nanoparticles attached to specific aptamer

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