Mechanistic study on reduction reaction of nitro compounds catalyzed by gold nanoparticles using in situ SERS monitoring

Cui, Qianling; Yashchenok, Alexey M.; Li, Lidong; Möhwald, Helmuth; Bargheer, Matias

doi:10.1016/j.colsurfa.2015.01.075

Cited by 24 publications

(14 citation statements)

References 29 publications

(38 reference statements)

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“…It has to be mentioned here that although the reduction from 4‐NTP to 4‐ATP in sodium borohydride solution is widely used as a model reaction in metal nanostructure catalysis, the reaction mechanism remains unclear. It is easy to understand the catalytic reduction of 4‐NTP when the catalyst touches the nitro groups . However, when 4‐NTP molecules directly interact with the metal catalysts via –SH groups, the –NO 2 groups have no direct contact with the metal surface.…”

Section: Resultsmentioning

confidence: 98%

Label‐free SERS monitoring of hydride reduction catalyzed by Au nanostars

König

Radojčić

Schlücker

et al. 2016

J Raman Spectroscopy

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Surface‐enhanced Raman scattering (SERS) is a promising molecular spectroscopic technique to study chemical reactions catalyzed by nobel metal nanoparticles. Herein, the Au nanostar (NS)‐catalyzed hydride reduction of 4‐nitrothiophenol to 4‐aminothiophenol chemisorbed at the metal/solution interface was followed by SERS. By developing a simple two‐step route, we demonstrated shape‐controlled synthesis and morphology‐dependent catalytic activity of AuNSs. The kinetic SERS monitoring of the reaction on the Au surface indicates that the catalytic activity of the AuNSs correlates with the sharpness of their tips. This is consistent with the known size‐dependent catalytic activity of small AuNPs. In contrast to the complex bifunctional nanostructures reported previously, this work shows that AuNSs are bifunctional nanostructures suitable for investigating Au‐catalyzed reactions. A proposed electron transfer mechanism explains the reduction of 4‐nitrothiophenol to 4‐aminothiophenol on AuNS tips where –NO2 groups have no direct contact with the catalyst. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Resultsmentioning

confidence: 98%

Label‐free SERS monitoring of hydride reduction catalyzed by Au nanostars

König

Radojčić

Schlücker

et al. 2016

J Raman Spectroscopy

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“…A shift of the corresponding absorbance peak at 315 nm to 400 nm occurred immediately after the addition of NaBH 4 . This new peak (at 400 nm) is attributed [ 27 , 28 , 29 , 30 , 31 , 32 ] to the 4-nitrophenolate ion formed in the presence of NaBH 4 .…”

Section: Resultsmentioning

confidence: 99%

“…In particular, the reduction of 4-nitrophenol has become the model reaction for the evaluation of the catalytic activity of metallic NPs, namely with Ag [ 25 , 26 ], Au [ 27 , 28 , 29 , 30 , 31 , 32 ], or Pd [ 33 ] metals. The existence of a well-defined absorption band characteristic of this substrate allows to easy screening of the reaction by UV–vis spectroscopy [ 34 , 35 , 36 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Phenolic Compounds on the Synthesis of Gold Nanoparticles and its Catalytic Activity in the Reduction of Nitro Compounds

et al. 2018

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Gold nanoparticles (AuNPs) were prepared using an eco-friendly approach in a single step by reduction of HAuCl4 with polyphenols from tea extracts, which act as both reducing and capping agents. The obtained AuNPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible spectroscopy (UV–vis), and X-ray photoelectron spectroscopy (XPS). They act as highly efficient catalysts in the reduction of various aromatic nitro compounds in aqueous solution. The effects of a variety of factors (e.g., reaction time, type and amount of reducing agent, shape, size, or amount of AuNPs) were studied towards the optimization of the processes. The total polyphenol content (TPC) was determined before and after the catalytic reaction and the results are discussed in terms of the tea extract percentage, the size of the AuNPs, and their catalytic activity. The reusability of the AuNP catalyst in the reduction of 4-nitrophenol was also tested. The reactions follow pseudo first-order kinetics.

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“…Gold nanoparticles are interesting materials due to their unique chemical and physical properties , and they can be applied in many areas of science, e.g., medicine , catalysis , and materials engineering . Today, the process of particles synthesis is well known , and in principle it can be divided into chemical and physical methods .…”

Section: Introductionmentioning

confidence: 99%

Gold Nanoparticles Formation via Au(III) Complex Ions Reduction with l -Ascorbic Acid

Luty–Błocho

Wojnicki

Fitzner

2017

Int. J. Chem. Kinet.

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In this paper, the kinetics and mechanism of gold nanoparticles formation during the redox reaction between [AuCl 4 ]¯complex and L-ascorbic acid under different conditions were described. It was also shown that reagent concentration, chloride ions, and pH influence kinetics of nucleation and growth. To establish rate constants of these stages, the model of Finke and Watzky was applied. From Arrhenius and Eyring dependencies, the values of activation energy (22.5 kJ mol −1 for the nucleation step and 30.3 kJ mol −1 for the growth step), entropy (about −228 J K −1 mol −1 for the nucleation step and −128 J K −1 mol −1 for the growth step), and enthalpy (19.8 kJ mol −1 for nucleation and 27.8 kJ mol −1 for particles growth) were determined. It was also shown that the disproporationation reaction had influence on the rate of nanoparticles formation and may have impact on final particles morphology. C 2017 Wiley Periodicals, Inc. Int J Chem Kinet 49: [789][790][791][792][793][794][795][796][797] 2017

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Mechanistic study on reduction reaction of nitro compounds catalyzed by gold nanoparticles using in situ SERS monitoring

Cited by 24 publications

References 29 publications

Label‐free SERS monitoring of hydride reduction catalyzed by Au nanostars

Label‐free SERS monitoring of hydride reduction catalyzed by Au nanostars

Effect of Phenolic Compounds on the Synthesis of Gold Nanoparticles and its Catalytic Activity in the Reduction of Nitro Compounds

Gold Nanoparticles Formation via Au(III) Complex Ions Reduction with l -Ascorbic Acid

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