Shape- and Size-Controlled Fabrication of Gold Nano-Urchins via Use of a Mixed Sodium Borohydride and Ascorbic Acid Reductant System.
Langmuir
; 37(36): 10702-10707, 2021 Sep 14.
Article
em En
| MEDLINE
| ID: mdl-34464146
ABSTRACT
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 = 111 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 32. 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.
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Base de dados:
MEDLINE
Assunto principal:
Nanopartículas Metálicas
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Ouro
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article