Synthesis of contiguous silica-gold core-shell structures: Critical parameters and processes

Nopphawan Phonthammachai; James C.Y. Kah; Guo Jun; Colin J.R. Sheppard; Malini C. Olivo; Subodh G. Mhaisalkar; Timothy J. White

doi:10.1021/la703580r

Synthesis of contiguous silica-gold core-shell structures: Critical parameters and processes

Nopphawan Phonthammachai^*, James C.Y. Kah, Guo Jun, Colin J.R. Sheppard, Malini C. Olivo, Subodh G. Mhaisalkar, Timothy J. White

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

78 Citations (Scopus)

Abstract

A direct process for preparing contiguous gold shells (15-25 nm thick) over amorphous silica spheres (200 nm) is described. In this method, gold seeds are synthesized from HAuCl₄ in a dilute NaOH solution using deposition-precipitation with subsequent metallization by sodium borohydride (NaBH₄). The ease of dispersing gold nanocrystals on spheres of bare silica and spheres after grafting with ammonia was studied as a function of pH (4-8), reaction temperature (65-96 °C), and time (5-30 min). Additional parameters requiring optimization included the quantity of NaBH4 and the HAuCl₄ in K₂CO₃ solution to silica volume ratio. The evolution of gold nanocrystal growth was monitored by transmission electron microscopy, and the bathochromic shift of ultraviolet-visible absorption was correlated with shell perfection and thickness.

Original language	English
Pages (from-to)	5109-5112
Number of pages	4
Journal	Langmuir
Volume	24
Issue number	9
DOIs	https://doi.org/10.1021/la703580r
Publication status	Published - May 6 2008
Externally published	Yes

ASJC Scopus Subject Areas

General Materials Science
Condensed Matter Physics
Surfaces and Interfaces
Spectroscopy
Electrochemistry

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10.1021/la703580r

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title = "Synthesis of contiguous silica-gold core-shell structures: Critical parameters and processes",

abstract = "A direct process for preparing contiguous gold shells (15-25 nm thick) over amorphous silica spheres (200 nm) is described. In this method, gold seeds are synthesized from HAuCl4 in a dilute NaOH solution using deposition-precipitation with subsequent metallization by sodium borohydride (NaBH4). The ease of dispersing gold nanocrystals on spheres of bare silica and spheres after grafting with ammonia was studied as a function of pH (4-8), reaction temperature (65-96 °C), and time (5-30 min). Additional parameters requiring optimization included the quantity of NaBH4 and the HAuCl4 in K2CO3 solution to silica volume ratio. The evolution of gold nanocrystal growth was monitored by transmission electron microscopy, and the bathochromic shift of ultraviolet-visible absorption was correlated with shell perfection and thickness.",

author = "Nopphawan Phonthammachai and Kah, {James C.Y.} and Guo Jun and Sheppard, {Colin J.R.} and Olivo, {Malini C.} and Mhaisalkar, {Subodh G.} and White, {Timothy J.}",

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T2 - Critical parameters and processes

AU - Phonthammachai, Nopphawan

AU - Kah, James C.Y.

AU - Jun, Guo

AU - Sheppard, Colin J.R.

AU - Olivo, Malini C.

AU - Mhaisalkar, Subodh G.

AU - White, Timothy J.

PY - 2008/5/6

Y1 - 2008/5/6

N2 - A direct process for preparing contiguous gold shells (15-25 nm thick) over amorphous silica spheres (200 nm) is described. In this method, gold seeds are synthesized from HAuCl4 in a dilute NaOH solution using deposition-precipitation with subsequent metallization by sodium borohydride (NaBH4). The ease of dispersing gold nanocrystals on spheres of bare silica and spheres after grafting with ammonia was studied as a function of pH (4-8), reaction temperature (65-96 °C), and time (5-30 min). Additional parameters requiring optimization included the quantity of NaBH4 and the HAuCl4 in K2CO3 solution to silica volume ratio. The evolution of gold nanocrystal growth was monitored by transmission electron microscopy, and the bathochromic shift of ultraviolet-visible absorption was correlated with shell perfection and thickness.

AB - A direct process for preparing contiguous gold shells (15-25 nm thick) over amorphous silica spheres (200 nm) is described. In this method, gold seeds are synthesized from HAuCl4 in a dilute NaOH solution using deposition-precipitation with subsequent metallization by sodium borohydride (NaBH4). The ease of dispersing gold nanocrystals on spheres of bare silica and spheres after grafting with ammonia was studied as a function of pH (4-8), reaction temperature (65-96 °C), and time (5-30 min). Additional parameters requiring optimization included the quantity of NaBH4 and the HAuCl4 in K2CO3 solution to silica volume ratio. The evolution of gold nanocrystal growth was monitored by transmission electron microscopy, and the bathochromic shift of ultraviolet-visible absorption was correlated with shell perfection and thickness.

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Synthesis of contiguous silica-gold core-shell structures: Critical parameters and processes

Abstract

ASJC Scopus Subject Areas

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