Revealing Controlled Etching Behaviors of Gold Nanobipyramids by Carbon Film Liquid Cell Transmission Electron Microscopy

Abstract

Regulation and design of material structure is very attractive and important for achieving special properties. Oxidative etching can be used to design nanomaterials with a variety of structures. It is crucial to reveal the structural evolution and etching mechanism. Here, the etching processes of gold nanobipyramids (Au NBPs) are observed in the presence of O2 and Cl– ions serving as oxidative etchants by in situ liquid cell transmission electron microscopy (TEM). By controlling [AuCl4]− ions, two types of etching pathways are characterized: (1) a fast nonequilibrium oxidative etching process during which Cl– ions are uniformly adsorbed on the surface of Au NBPs and a rod intermediate is formed that eventually dissolves in aqueous solutions with only HCl and (2) a slow equilibrium oxidative etching process during which atomic etching takes place at tips or edges and a small amount of Au NBPs is dissolved to reach a dynamic equilibrium with the addition of HAuCl4. The addition of ions to adjust the material structure can provide guidance for material design and application.

Characterization of Nanomaterials Using In Situ Liquid-Cell Transmission Electron Microscopy: A Review

“…There have been many similar reports on various metals, − ,− oxides, − and alloys − ,− in recent years. Dynamic imaging observation of corroded nanoscale microstructure features in liquid-cell TEM has exciting application prospects.…”

Agglomeration compaction promotes corrosion of gold nanoparticles

“…950 nm) appears, which, by analogy with other researchers, can be attributed to the impact of nanoparticle aggregation in elongated geometry. [41][42][43] At times above ∼80 min, absorption bands in UV-VIS spectrum essentially overlap. The uncertainty of the process of deconvolution of the A(n)/n spectra into elementary bands and the large residuals of the approximating functional do not allow to apply this procedure in such case.…”

Preparation of boron-doped diamond microelectrodes to determine the distribution size of platinum nanoparticles using current transient method

“…Based on the results, the potential of +0.4 V was selected to study the correlation between the current transient of Pt NPs due to hydrazine oxidation with the size distribution of the prepared nanoparticles using chronoamperometry on Au and BDD microelectrodes, taking advantage of the collision and adhesion of Pt NPs to the microelectrode surface (Jung et al, 2019). It was expected that this effect is likely acted to contribute in the electrocatalytic oxidation of hydrazine at the microelectrodes (Jung et al, 2019;Wei et al, 2023). Chronoamperometry was performed by immersing each microelectrode in a 25 mL solution of hydrazine (15 mM) in PBS (50 mM) pH 7.4 to investigate the noise of hydrazine oxidation currents.…”

“…To achieve a comprehensive understanding of their fundamental properties and optimize their performance for various applications, it is crucial to accurately characterize nanoparticles in terms of size, shape, and composition. Currently, methods like transmission electron microscopy (TEM), scanning electron microscopy (SEM), and particle size analyzers (PSA) are commonly used for nanoparticle size characterization (Wei et al, 2023). However, these techniques are expensive and require extensive maintenance (Navalón & García, 2016).…”