Shape- and Size-Controlled Fabrication of Gold Nano-Urchins via Use of a Mixed Sodium Borohydride and Ascorbic Acid Reductant System
Urchin-shaped gold nanoparticles (AuNUs) are anisotropic nanomaterials with unique chemical and physical properties of interest for a variety of applications. However, synthesizing AuNUs with controlled sizes and shapes remains challenging. We demonstrate that a combination of sodium borohydride (Na...
Saved in:
Published in | Langmuir Vol. 37; no. 36; pp. 10702 - 10707 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
American Chemical Society
14.09.2021
|
Online Access | Get full text |
Cover
Loading…
Summary: | Urchin-shaped gold nanoparticles (AuNUs) are anisotropic nanomaterials with unique chemical and physical properties of interest for a variety of applications. However, synthesizing AuNUs with controlled sizes and shapes remains challenging. We demonstrate that a combination of sodium borohydride (NaBH4) and ascorbic acid (AA) as reducing agents can produce an aqueous dispersion of AuNUs after just 9 min at room temperature (25 °C). The AuNUs were size- and shape-controlled using a molar ratio for NaBH4/AA/HAuCl4 = 1:1:1 at pH 3. The added aurate was almost entirely (98.8%) consumed in the formation of AuNUs. The resultant AuNU concentration was 1.1 × 1010 particles/mL. The diameters observed in transmission electron microscopy were 145.1 ± 37.4 nm. The AuNUs had an average of 12 spikes and an average volume of 3.7 × 105 nm3. The partition volume between the spikes and the core of particles was 3:2. The AuNUs had a pink color and exhibited an absorption wavelength maximum at 540 nm. It is assumed that the AuNUs originate from icosahedral seeds and urchin shapes emerge from connecting smaller-sized seeds and larger-sized core particles. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0743-7463 1520-5827 |
DOI: | 10.1021/acs.langmuir.1c01303 |