Silver nanoparticle catalyzed reduction of aromatic nitro compounds

Pradhan, Narayan; Pal, Anjali; Pal, Tarasankar

doi:10.1016/s0927-7757(01)01040-8

Cited by 916 publications

(696 citation statements)

References 24 publications

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“…The reduced Hg 0 gets deposited onto the Ag surface forming an alloy of Hg-Ag, which is reported as lumps in earlier reports with the help of scanning electron microscopy observation. (43,45) The oxidation of AgNPs by Hg 2+ therefore decreases the concentration of AgNPs, and decolors the solution resulting in decreased absorption peak intensity.…”

Section: Agnp-based Detection Of Hg 2+mentioning

confidence: 99%

“…In this redox reaction, such unexpected rapid redox reaction between the zero-valent Ag 0 and the divalent Hg 2+ occurs owing to the nanoscale nature of AgNPs, which heightens the effective variation between the Ag + /Ag nano and Hg 2+ /Hg redox potentials and would favor the reduction of Hg 2+ to Hg 0 with the partial oxidation of Ag 0 . (18,21,39,(43)(44)(45) Owing to the high affinity between Ag 0 and Hg 0 , the reduced Hg 0 gets deposited onto the Ag surface, resulting in the formation of the Hg-Ag alloy. (18,21,43,44) This further results in a decreased intensity and blue shift.…”

Section: Agnp-based Detection Of Hg 2+mentioning

confidence: 99%

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Green Synthesis of Silver Nanoparticles Using Panax Ginseng Root Extract for the Detection of Hg2+

Tagad¹,

Hyun²,

Rucha³

et al. 2017

Sensors and Materials

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Exploring biomaterials/molecules as a reducing/capping agent for the synthesis of metal nanoparticles has set a new trend in green nanotechnology with improved environmental safety. Herein, a facile, one-pot, and green synthesis of silver nanoparticles (AgNPs) was achieved using Panax ginseng root extract that was obtained from the root powder as a cost-effective and environmentfriendly biomaterial. Optical, functional, and morphological characteristics of the synthesized AgNPs were determined using ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) spectrophotometers, transmission electron microscopy (TEM), and atomic force microscopy (AFM). The synthesized AgNPs were used for the detection of Hg 2+ by obtaining the absorption spectrum of the compound as a function of Hg 2+ concentration, which resulted in a decrease in absorption peak intensity with a slight blue shift. The AgNP solution decolored upon dissolution due to the formation of an Ag-Hg amalgam. The sensing characteristics were found to be linear when tested from 10 µM to 1 mM Hg 2+ concentration and the detection limit was estimated as 5 µM. To check the selectivity of the sensor towards Hg 2+ , the sensor response was measured for different heavy metals such as K + , Na + , Cu 2+ , Ni 2+ , Ca 2+ , Zn 2+ , Mg 2+ , and Mn 2+ , at 10 mM concentrations.

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Section: Agnp-based Detection Of Hg 2+mentioning

confidence: 99%

Section: Agnp-based Detection Of Hg 2+mentioning

confidence: 99%

Green Synthesis of Silver Nanoparticles Using Panax Ginseng Root Extract for the Detection of Hg2+

Tagad¹,

Hyun²,

Rucha³

et al. 2017

Sensors and Materials

View full text Add to dashboard Cite

show abstract

“…Silver nanoparticles have drawn much attention in research due to their many desirable properties including high electrical conductivity [23], excellent catalytic activity in organic redox reactions [16,24], surface plasmon resonance [3,10] and anti-microbial properties [7,14]. Synthesis of silver nanoparticles typically involves "bottom-up" reduction of silver salts, most commonly silver nitrate, often in the presence of capping agents to fine-tune particle sizes and shapes [11,12,[19][20][21]25,26].…”

Section: Introductionmentioning

confidence: 99%

Silver nanoparticle synthesis using lignin as reducing and capping agents: A kinetic and mechanistic study

Hsieh

2016

International Journal of Biological Macromolecules

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a b s t r a c tSilver nanoparticles (AgNPs) were robustly synthesized from aqueous AgNO 3 with alkali lignin (low sulfonate) (AL ls ) severing as dual reducing and capping agent. The AgNP synthesis mechanisms were highly pH dependent. Under neutral and acidic conditions, polydispersed AgNPs were synthesized via the self-catalyzed reduction of Ag + on instantaneously formed Ag 2 O surfaces followed by the slower pseudo-first order reduction. The Ag 2 O nanoparticles functioned as the nucleating sites for the reduction of remaining silver cations to form AgNPs whose size and size distribution strongly dependent of lignin concentrations. AgNPs were optimally synthesized by reducing 2 mmol/L AgNO 3 with 0.16 wt% AL ls at pH 10 and 85• C in 30 min to near 100% yield in bimodal distributed sizes with 23% and 77% in feret diameters of 7.3 (±2.2) nm and 14.3 (±1.8) nm, respectively.

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“…Because of their higher surface area and greater active sites for interaction with pollutants, pore volume, adjustable pore diameter, easy surface modification, and excellent biocompatibility, these materials are useful in the field of adsorption and separation. Mesoporous silica nano-based composites with different porosity characteristics such as size, shape, and relationship between porosity and with different morphologies have been widely described in the literature [35,36]. Among this family of materials, MCM-41 and SBA-15 types of mesoporous silica containing one-and twodimensional cylindrical channels have mostly been studied.…”

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confidence: 99%

The removal of mercury (II) from water by Ag supported on nanomesoporous silica

2016

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In this study, the synthesis of SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %) has been investigated under acidic conditions by using P123 as a template via the direct method. The nanocomposites of SBA-15 were synthesized by the same method and by the addition of silver salt. Finally, the nanocomposite materials were examined for the removal of mercury ions from wastewater as an adsorbent by the reverse titration method. Characterization was carried out through x-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N 2 adsorption-desorption (Brunauer-EmmettTeller). XRD spectra confirmed the presence of silver nanoparticles within the amorphous silica matrix of SBA-15. The Barrett-Joyner-Halenda analysis showed that SBA-15 and SBA-15/Ag have a narrow pore size distribution. SEM images demonstrated that the morphology of the matrix of SBA-15 is in spherical state. Furthermore, wavelength dispersive x-ray spectroscopy identified the presence and distribution of silver nanoparticles inside the pore channels and outside of them. Typical TEM images of SBA-15 and SBA-15/Ag (5 wt.%) indicated a regular hexagonal pore structure with long-range order and long channels. In SBA-15/Ag (5 wt.%) sample, the nanoparticles of silver was found into the pores and outside of them. The removal of mercury ions from wastewater using mesoporous silica nanocomposite containing silver nanoparticles was studied by the reverse titration analysis. The best capacity of adsorption of mercury ions from wastewater was obtained for SBA-15/Ag (5 wt.%) sample, which was equal to 42.26 mg/g in 20 min at pH of 7. The Freundlich model was used to explain the adsorption characteristics for the heterogeneous surface, and K f (adsorption capacity) and n (adsorption intensity) were determined for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %). The value of R 2 was about 0.99, 0.99, 0.98, and 0.98 and K f was about 42, 48, 58, and 58 mg/g for SBA-15/Ag, SBA-15/Ag (2.5 %), SBA-15/Ag (5 %), and SBA-15/Ag (10 %), respectively. Furthermore, the values of n >1 show a favorable adsorption process for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials. Moreover, the Langmuir isotherm model evaluation showed that the correlation coefficients for all concentrations were R 2 >0.99, indicating that Hg (II) ions were adsorbed on the surface of SBA-15/Ag via chemical and physical interaction. Additionally, the analytic hierarchy process (AHP) and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methods that depend on the criteria of the surface area, amount of adsorbent, pore volume, and cost of synthesis were used. The evaluation of results showed that the best sample was SBA-15/Ag (5 wt.%). Furthermore, the research work highlighted the antibacterial nanocomposite with suitable adsorption of Hg (II) ions from water solutions and supported its potential for environme...

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Silver nanoparticle catalyzed reduction of aromatic nitro compounds

Cited by 916 publications

References 24 publications

Green Synthesis of Silver Nanoparticles Using Panax Ginseng Root Extract for the Detection of Hg2+

Green Synthesis of Silver Nanoparticles Using Panax Ginseng Root Extract for the Detection of Hg2+

Silver nanoparticle synthesis using lignin as reducing and capping agents: A kinetic and mechanistic study

The removal of mercury (II) from water by Ag supported on nanomesoporous silica

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