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Galvanic synthesis of three-dimensional and hollow metallic nanostructures.

Park SH, Son JG, Lee TG, Kim J, Han SY, Park HM, Song JY - Nanoscale Res Lett (2014)

Bottom Line: Finally, the wet etching process of remaining silver resulted in the formation of 3D-NPG.During the GRR process, the application of bias voltage to the cathode decreased the porosity of 3D-NPG in the voltage range of 0.2 to -0.62 V.The 3D-NPG nanostructures were found to effectively enhance the SERS sensitivity of rhodamine 6G (R6G) molecules with a concentration up to 10(-8) M.

View Article: PubMed Central - PubMed

Affiliation: Korea Research Institute of Standard and Science, Daejeon, 305-340, Republic of Korea, psh@kriss.re.kr.

ABSTRACT
We report a low-cost, facile, and template-free electrochemical method of synthesizing three-dimensional (3D) hollow metallic nanostructures. The 3D nanoporous gold (3D-NPG) nanostructures were synthesized by a galvanic replacement reaction (GRR) using the different reduction potentials of silver and gold; hemispherical silver nanoislands were electrochemically deposited on cathodic substrates by a reverse-pulse potentiodynamic method without templates and then nanoporous gold layer replicated the shape of silver islands during the GRR process in an ultra-dilute electrolyte of gold(III) chloride trihydrate. Finally, the wet etching process of remaining silver resulted in the formation of 3D-NPG. During the GRR process, the application of bias voltage to the cathode decreased the porosity of 3D-NPG in the voltage range of 0.2 to -0.62 V. And the GRR process of silver nanoislands was also applicable to fabrication of the 3D hollow nanostructures of platinum and palladium. The 3D-NPG nanostructures were found to effectively enhance the SERS sensitivity of rhodamine 6G (R6G) molecules with a concentration up to 10(-8) M.

No MeSH data available.


Tilted SEM images of 3D nanoporous platinum and 3D-nanoshell palladium nanostructures. The insets denote the tilted and top-view SEM images with a higher magnification, respectively.
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Fig6: Tilted SEM images of 3D nanoporous platinum and 3D-nanoshell palladium nanostructures. The insets denote the tilted and top-view SEM images with a higher magnification, respectively.

Mentions: The GRR process was utilized to synthesize 3D nanoporous platinum and 3D-nanoshell palladium structures, as shown in Figure 6. Figure 6a shows the typical SEM images of ultra-thin 3D nanoporous platinum nanostructures produced by the GRR process in a 50 μM H2PtCl6 · xH2O solution and a selective etching process. The redox reaction of silver and PtCl62- occurs following Equation 2 [24]. The 3D nanoporous platinum structures had smaller nanopores and face-centered cubic crystal structure, as indexed by TEM and electron diffraction pattern analyses (Additional file 1: Figure S5).Figure 6


Galvanic synthesis of three-dimensional and hollow metallic nanostructures.

Park SH, Son JG, Lee TG, Kim J, Han SY, Park HM, Song JY - Nanoscale Res Lett (2014)

Tilted SEM images of 3D nanoporous platinum and 3D-nanoshell palladium nanostructures. The insets denote the tilted and top-view SEM images with a higher magnification, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493846&req=5

Fig6: Tilted SEM images of 3D nanoporous platinum and 3D-nanoshell palladium nanostructures. The insets denote the tilted and top-view SEM images with a higher magnification, respectively.
Mentions: The GRR process was utilized to synthesize 3D nanoporous platinum and 3D-nanoshell palladium structures, as shown in Figure 6. Figure 6a shows the typical SEM images of ultra-thin 3D nanoporous platinum nanostructures produced by the GRR process in a 50 μM H2PtCl6 · xH2O solution and a selective etching process. The redox reaction of silver and PtCl62- occurs following Equation 2 [24]. The 3D nanoporous platinum structures had smaller nanopores and face-centered cubic crystal structure, as indexed by TEM and electron diffraction pattern analyses (Additional file 1: Figure S5).Figure 6

Bottom Line: Finally, the wet etching process of remaining silver resulted in the formation of 3D-NPG.During the GRR process, the application of bias voltage to the cathode decreased the porosity of 3D-NPG in the voltage range of 0.2 to -0.62 V.The 3D-NPG nanostructures were found to effectively enhance the SERS sensitivity of rhodamine 6G (R6G) molecules with a concentration up to 10(-8) M.

View Article: PubMed Central - PubMed

Affiliation: Korea Research Institute of Standard and Science, Daejeon, 305-340, Republic of Korea, psh@kriss.re.kr.

ABSTRACT
We report a low-cost, facile, and template-free electrochemical method of synthesizing three-dimensional (3D) hollow metallic nanostructures. The 3D nanoporous gold (3D-NPG) nanostructures were synthesized by a galvanic replacement reaction (GRR) using the different reduction potentials of silver and gold; hemispherical silver nanoislands were electrochemically deposited on cathodic substrates by a reverse-pulse potentiodynamic method without templates and then nanoporous gold layer replicated the shape of silver islands during the GRR process in an ultra-dilute electrolyte of gold(III) chloride trihydrate. Finally, the wet etching process of remaining silver resulted in the formation of 3D-NPG. During the GRR process, the application of bias voltage to the cathode decreased the porosity of 3D-NPG in the voltage range of 0.2 to -0.62 V. And the GRR process of silver nanoislands was also applicable to fabrication of the 3D hollow nanostructures of platinum and palladium. The 3D-NPG nanostructures were found to effectively enhance the SERS sensitivity of rhodamine 6G (R6G) molecules with a concentration up to 10(-8) M.

No MeSH data available.