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Size-controlled synthesis of monodispersed gold nanoparticles via carbon monoxide gas reduction.

Young JK, Lewinski NA, Langsner RJ, Kennedy LC, Satyanarayan A, Nammalvar V, Lin AY, Drezek RA - Nanoscale Res Lett (2011)

Bottom Line: It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas.Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%.Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electrical and Computer Engineering, Rice University, MS-366, 6100 Main St,, Houston, TX 77005, USA. drezek@rice.edu.

ABSTRACT
An in depth analysis of gold nanoparticle (AuNP) synthesis and size tuning, utilizing carbon monoxide (CO) gas as a reducing agent, is presented for the first time. The sizes of the AuNPs are tunable from ~4 to 100 nm by altering the concentration of HAuCl4 and inlet CO gas-injection flow rate. It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas. Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%. Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification. The time necessary to synthesize AuNPs, using CO, is less than 2 min.

No MeSH data available.


Effect of pH on nanoparticle spectrum. UV-visible spectra of AuNPs produced from a 0.1 mM HAuCl4 aqueous solution synthesized at varying pH values.
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Figure 6: Effect of pH on nanoparticle spectrum. UV-visible spectra of AuNPs produced from a 0.1 mM HAuCl4 aqueous solution synthesized at varying pH values.

Mentions: Figure 6 shows UV-visible absorption spectra of AuNPs prepared by reduction of hydrolyzed HAuCl4 at various pH. At pH = 4.25, the acquired AuNPs exhibited a symmetric spectrum with a surface plasmon resonance (SPR) peak at 512 nm. When the pH increased to 6.6, there was a SPR shift to 527 nm. When the pH increased to 7.45, the SPR peak position did not change much at 528 nm, and the SPR peak remained symmetric. The SPR feature changed abruptly when the pH was 9.34 showing a broad feature originating at 559 nm. The SPR peak red-shifted further when the pH increased to 10.3. Absorption in the NIR region also gained significant intensity.


Size-controlled synthesis of monodispersed gold nanoparticles via carbon monoxide gas reduction.

Young JK, Lewinski NA, Langsner RJ, Kennedy LC, Satyanarayan A, Nammalvar V, Lin AY, Drezek RA - Nanoscale Res Lett (2011)

Effect of pH on nanoparticle spectrum. UV-visible spectra of AuNPs produced from a 0.1 mM HAuCl4 aqueous solution synthesized at varying pH values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211845&req=5

Figure 6: Effect of pH on nanoparticle spectrum. UV-visible spectra of AuNPs produced from a 0.1 mM HAuCl4 aqueous solution synthesized at varying pH values.
Mentions: Figure 6 shows UV-visible absorption spectra of AuNPs prepared by reduction of hydrolyzed HAuCl4 at various pH. At pH = 4.25, the acquired AuNPs exhibited a symmetric spectrum with a surface plasmon resonance (SPR) peak at 512 nm. When the pH increased to 6.6, there was a SPR shift to 527 nm. When the pH increased to 7.45, the SPR peak position did not change much at 528 nm, and the SPR peak remained symmetric. The SPR feature changed abruptly when the pH was 9.34 showing a broad feature originating at 559 nm. The SPR peak red-shifted further when the pH increased to 10.3. Absorption in the NIR region also gained significant intensity.

Bottom Line: It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas.Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%.Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electrical and Computer Engineering, Rice University, MS-366, 6100 Main St,, Houston, TX 77005, USA. drezek@rice.edu.

ABSTRACT
An in depth analysis of gold nanoparticle (AuNP) synthesis and size tuning, utilizing carbon monoxide (CO) gas as a reducing agent, is presented for the first time. The sizes of the AuNPs are tunable from ~4 to 100 nm by altering the concentration of HAuCl4 and inlet CO gas-injection flow rate. It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas. Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%. Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification. The time necessary to synthesize AuNPs, using CO, is less than 2 min.

No MeSH data available.