Photochemical formation of silver‐gold (AgAu) composite colloids in solutions containing sodium alginate

Sato, Tomoo; Kuroda, Shigeru; Takami, Akinori; Yonezawa, Yoshiro; Hada, Hiroshi

doi:10.1002/aoc.590050409

Cited by 63 publications

(40 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the citrate is a reducing agent that can be photo-oxidized to acetone-1,3-dicarboxylate, as well as carbon dioxide, according to Ahern and Garrell [32] and Sato et al [33] and their adsorption onto the nanoparticle surface induces an electron transfer. [28] According to Maillard et al [28] after being formed, the seeds absorb light isotropically (equally for all orientations) due to their spherical shape.…”

Section: Resultsmentioning

confidence: 99%

Silver nanoparticles synthesized by direct photoreduction of metal salts. Application in surface‐enhanced Raman spectroscopy

Sato-Berrú

Redón

Vázquez-Olmos

et al. 2008

J Raman Spectroscopy

View full text Add to dashboard Cite

A simple synthesis method of silver nanoparticles and its application as an active surface-enhanced Raman spectroscopy (SERS) colloid are presented in this work. The photoreduction of AgNO 3 in presence of sodium citrate (NaCit) was carried out by irradiation with different light sources (UV, white, blue, cyan, green, and orange) at room temperature. The evaluation of silver nanoparticles obtained as a function of irradiation time (1-24 h) and light source was followed by UV-visible absorption spectroscopy. This light-modification process results in a colloid with distinctive optical properties that can be related to the size and shape of the particles. The Ag colloids, as prepared, were employed as active colloids in SERS. Pyridine and caffeine were used as test molecules.

show abstract

Section: Resultsmentioning

confidence: 99%

Silver nanoparticles synthesized by direct photoreduction of metal salts. Application in surface‐enhanced Raman spectroscopy

Sato-Berrú

Redón

Vázquez-Olmos

et al. 2008

J Raman Spectroscopy

View full text Add to dashboard Cite

show abstract

“…Photochemical reduction is an attractive means of accomplishing this end, as it allows for complete mixing of the reagents before the synthesis is initiated. Whereas a number of groups have reported photochemical syntheses of silver nanoparticles [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], in all of this previous work, the resultant nanoparticles have been polydisperse and often relatively large as well. The polydispersity of the particles produced is probably related to the fact that these syntheses involve ultraviolet exposure times of many minutes.…”

mentioning

confidence: 91%

Photochemical Synthesis and Multiphoton Luminescence of Monodisperse Silver Nanocrystals

et al. 2006

View full text Add to dashboard Cite

A rapid, photochemical solution-phase synthesis has been developed for the production of monodisperse, nanometer-sized silver particles. The stabilizer used in the synthesis can be used to control the average diameter of the particles over a range from 1 to 7 nm. The same reaction mixture can also be employed to deposit patterns of nanoparticles with a laser via multiphoton absorption. The particles exhibit strong multiphoton absorption-induced luminescence when irradiated with 800-nm light, allowing emission from single nanoparticles to be observed readily.Keywords Silver nanoparticle . Photochemical synthesis . Multiphoton absorption . LuminescenceApplications of noble-metal nanoparticles have grown exponentially over the past decade. Silver is one of the least expensive of the noble metals and is only weakly reactive in the bulk. In nanoparticle form, silver has properties that can be exploited for applications such as surface-enhanced Raman spectroscopy (SERS) [1], even down to the single-molecule level [2,3]. In addition, subnanometer silver clusters show considerable promise as luminescent media for single-molecule studies [4,5]. Although the preparation of monodisperse nanoclusters of metals such as gold and platinum with average diameters that can be less than 1 nm is well documented [6,7], the synthesis of monodisperse silver nanoclusters is generally a considerably more difficult prospect, and it has been difficult to attain diameters of less than 3 nm in solution [8,9]. Here we report a facile solution-phase photochemical synthesis that, in a matter of minutes, produces monodisperse silver nanoclusters with controllable average diameters that can range from 1 to 7 nm. We further show that two-photon absorption (TPA) can be used to pattern the nanoparticles on a substrate. In addition, the particles exhibit strong multiphoton-absorption-induced luminescence (MAIL) upon irradiation with ultrafast pulses of 800-nm light, allowing the emission of individual particles to be monitored.The role of kinetics in determining the average size and dispersity of semiconductor nanoparticles has long been recognized and used to advantage [10]. Many such schemes require the rapid mixing of precursors to initiate the synthesis of nanoparticles. However, this type of strategy has received considerably less attention in the synthesis of noble-metal nanoparticles. A key element in such an approach is the ability to reduce silver cations quickly, such that nanoparticles with small diameters can be trapped kinetically. Photochemical reduction is an attractive means of accomplishing this end, as it allows for complete mixing of the reagents before the synthesis is initiated. Whereas a number of groups have reported photochemical syntheses of silver nanoparticles [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], in all of this previous work, the resultant nanoparticles have been polydisperse and often relatively large as well. The polydispersity of the particles produced is probably related to the fact that the...

show abstract

“…Figure (a) shows the absorbance intensity at 440 nm versus S i Tot for all the processing parameters studied. It is worth noting that for a constant extinction coefficient of ∼10 8 M −1 cm −1 based on an average nanoparticle diameter of ≈10 nm from SEM analysis, the particle number concentrations are in the range of ∼10 17 cm −3 . From this analysis, a clear correlation is found between particle concentration in the films and S i Tot .…”

Section: Resultsmentioning

confidence: 99%

Correlating charge fluence with nanoparticle formation during in situ plasma synthesis of nanocomposite films

Ghosh

Boris

Hernández

et al. 2017

Plasma Processes & Polymers

View full text Add to dashboard Cite

Plasmas enable the fabrication of nanocomposites via in situ reduction of metal precursors dispersed in polymer films. The mechanism for reduction has not yet been revealed and it is not known how plasma parameters affect nanoparticle formation. Here, we present a systematic study using a low‐pressure, pulsed electron beam generated argon plasma to treat silver cation‐containing polyacrylic acid films. The background pressure, treatment time, period, and pulse width are varied to influence charged species generation. We show a direct correlation between nanoparticle density, as assessed by ultraviolet‐visible absorbance analysis, and the charge fluence. Although the experiments could not separate the specific role of ions and electrons, our results demonstrate the importance of charged species to nanoparticle formation.

show abstract

Photochemical formation of silver‐gold (AgAu) composite colloids in solutions containing sodium alginate

Cited by 63 publications

References 27 publications

Silver nanoparticles synthesized by direct photoreduction of metal salts. Application in surface‐enhanced Raman spectroscopy

Silver nanoparticles synthesized by direct photoreduction of metal salts. Application in surface‐enhanced Raman spectroscopy

Photochemical Synthesis and Multiphoton Luminescence of Monodisperse Silver Nanocrystals

Correlating charge fluence with nanoparticle formation during in situ plasma synthesis of nanocomposite films

Contact Info

Product

Resources

About