Implications of Byproduct Chemistry in Nanoparticle Synthesis

Abstract

Byproducts in metal nanoparticle synthesis can interfere with nanomaterial formation and self-assembly, as well as the perceived nanomaterial properties. Such syntheses go through a complicated series of intermediates making it difficult to predict byproduct chemistry, and challenging to determine experimentally. By a combined experimental and theoretical approach, the formation of organic byproducts are mapped out for the synthesis of gold nanoparticles with the Good's buffer MES. Comprehensive nuclear magnetic resonance studies supported by mass spectrometry, ultraviolet-visible spectroscopy, and density functional theory reveal a number of previously unidentified byproducts formed by oxidation, C-N bond cleavage, and C-C bond formation. A reaction mechanism involving up to four consecutive oxidations is proposed. Oligomeric products with 2 electronic transitions in the visible range are suggested. This approach can be extended broadly, and lead to more informed synthesis design and materials characterization.

Gas Phase Synthesis of Multi-Element Nanoparticles

“…In this review, the focus lies on gas-phase methods, which offer the most precise size control and the greatest flexibility of choice of elements, especially with the production of multi-element NPs. In addition, NPs can be produced without the presence of ligands or surfactants, which can change their properties [19][20][21], though these can be added later if required. A further advantage, especially with ultra-high vacuum-(UHV-) based sources, is that nanoparticles can be prepared free of oxides, or they can be oxidized with a high degree of control.…”

2‐(N‐Morpholino)ethanesulphonic acid mediated facile and rapid one‐pot synthesis of gold nanoparticles and its application for colorimetric detection of heparin in human serum

“…The reaction mechanism of gold catalyzed oxidation of 2-(N-morpholino)ethanesulphonic acid. [38] As shown in Figure 3B,C, the AuNPs were spherical with an average diameter of 11.18 nm. As shown in Figure 3D, the zeta potential of the prepared AuNPs was measured to be À31.1 mV.…”

“…(A) The reaction mechanism of gold catalyzed oxidation of 2‐( N ‐morpholino)ethanesulphonic acid. [ 38 ] (B) The electrospray ionization‐high resolution mass spectrometry (ESI‐HRMS) spectrum of oxalic acid. (C) The ESI‐HRMS spectrum of 2‐((2‐hydroxyethyl) amino) ethane‐1‐sulphonic acid…”

“…[38] Additionally, as shown in Figure 1B,C, the molecular ion signals at 90.0142 (m/z, [M + H] + ) and 170.0498 (m/z, [M + H] + ) in the electrospray ionization-high resolution mass spectrometry (ESI-HRMS) spectrum were in accord with the molecular weight of oxalic acid and 2-((2-hydroxyethyl)amino) ethane-1-sulphonic acid, respectively. Compared with the methods previously reported, [38][39][40][41][42] this 'green' synthetic route could be completed in 1 min by fast blending on a Mini Vortex metre at room temperature without complicated operation or heating treatment, which not only simplifies and moderates the preparation procedure of AuNPs but also greatly shortens the reaction time. HAuCl 4 plays a crucial role in the synthesis of AuNPs, therefore, we explored the effect of HAuCl 4 concentration on the synthesis of AuNPs.…”