Identification of a Critical Intermediate in Galvanic Exchange Reactions by Single‐Nanoparticle‐Resolved Kinetics

Smith, J. Graham; Yang, Qing; Jain, Prashant K.

doi:10.1002/anie.201309307

Cited by 67 publications

(98 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Jain et al analyzed the LSPR intensity change of Ag nanospheres during the galvanic replacement reaction at the single-particle level, reporting that the sudden drop of the peak intensity is due to the bulk conversion from an Ag nanoparticle to a Au− Ag cage. 14 In comparison with the ex situ measurements, this in situ plasmon monitoring exhibits similar spectral changes with a significantly long initial waiting time. In the in situ monitoring, the reaction is conducted under the continuous slow flow rate of the reaction mixture, and thus the stochastic feature of the initial step can be fully detected.…”

Section: ■ Results and Discussionmentioning

confidence: 71%

“…It is not surprising that this sudden shift is also observed in bulk experiments and in a single-particle measurement of a Ag sphere. 14,24 As the reaction proceeds, the peak shifts to 590 nm for the reaction period up to 3 h. Then, the peak shows little change at ∼600 nm up to 24 The Journal of Physical Chemistry C Article h; however, the morphology in the microscopy images continuously changes to the hollow structure with a large cavity. Figure 3b represents a trend of the peak shifts for individual nanocubes, indicating the initial rapid red-shift and eventual steady state of the peak maximum.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…13 Jain et al analyzed the replacement reaction on Ag spheres using dark-field scattering at the single-particle level and identified a critical step in the nanosized void formation process followed by an exchange reaction with nonlinear reaction kinetics. 14 Although reasonable reaction sequences of galvanic replacement have been proposed based on data from multiple characterization techniques, the actual mechanism still needs to be explored in detail because the replacement reaction is highly sensitive to the reaction environment. The clear formation of Au−Ag nanoboxes only occurs at 100°C, and facet-specific replacement reactions are frequently observed under specific conditions.…”

Section: ■ Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Ex Situ and in Situ Surface Plasmon Monitoring of Temperature-Dependent Structural Evolution in Galvanic Replacement Reactions at a Single-Particle Level

et al. 2015

View full text Add to dashboard Cite

The galvanic replacement reaction has recently been established as a standard protocol to create complex hollow structures with various compositions and morphologies. In the present study, the structural evolution of Ag nanocubes with Au precursors is monitored at the single-particle level by means of ex situ and in situ characterization tools. We explore two important features distinct from previous observations. First, the peak maximum of localized surface plasmon resonance (LSPR) spectra abruptly shifts at the initial stage and reaches a steady wavelength of ∼600 nm; however, the structure continuously evolves to yield a nanobox even during the late stages of the reaction. This steady wavelength results from a balance of the LSPR between the red-shift by the growth of the inner cavity and the blue-shift by the deposition of Au on the interior, as confirmed by theoretical simulations. Second, the change in morphology at different temperatures is first analyzed by both ex situ and in situ monitoring methods. The reaction at 25°C forms granules on the surface, whereas the reaction at 60°C provides flat and even surfaces of the hollow structures due to the large diffusion rate of Ag atoms in Au at a higher temperature. These plasmon-based monitoring techniques have great potentials to investigate various heterogeneous reaction mechanisms at the single-particle level. ■ INTRODUCTIONFor the past several decades, metal nanostructures have been extensively studied due to their unique physical and chemical properties and versatile applications in many areas. To control the properties of metal nanostructures so as to make them suitable for specific applications, the creation of complex nanostructures with multiple components and high-dimensional morphologies has been attempted, such as core−shell, 1,2 hollow, 3,4 and branched nanoparticles. 5,6 For the fabrication of these nanostructures, solid-state chemical reactions on the nanoscale are commonly applied, including galvanic replacement, 7,8 void formation via the Kirkendall effect, 9 and cationic and anionic exchanges 10 as well as the induction of kinetic growth during the synthesis step. In particular, galvanic replacement has been established as a standard method to make complex hollow nanostructures with a variety of compositions and morphologies.Galvanic replacement is basically a redox process between two metals with distinct reduction potentials. Oxidation occurs on the metal with a low reduction potential, and the reduction and deposition concomitantly occur on the other metal with a high reduction potential. The replacement reaction is known as a major cause of the corrosion of metal surfaces in the bulk form, and Xia et al. revitalized it as a simple and versatile route for the generation of metal hollow nanostructures. 11 The formation mechanism of this reaction was elucidated through a change in the morphology as observed in TEM images along the reaction progress. These outcomes included the generation of a specific spot, a continuous hollow formation, mor...

show abstract

Section: ■ Results and Discussionmentioning

confidence: 71%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Ex Situ and in Situ Surface Plasmon Monitoring of Temperature-Dependent Structural Evolution in Galvanic Replacement Reactions at a Single-Particle Level

et al. 2015

View full text Add to dashboard Cite

show abstract

“…And k app1 and k app2 here correspond to k 1 and k 2 in the empirical eq 1, respectively. Using classic Langmuir−Hinshelwood kinetics for surface catalysis where AR and OH • adsorb onto different types of surface sites, we can derive that k app1 and k app2 take the (4) Here G A is the adsorption equilibrium constant of AR. G B is the equilibrium constant for H 2 O 2 adsorption to directly become two adsorbed OH • .…”

Section: Resultsmentioning

confidence: 99%

Single-Molecule Kinetics Reveals a Hidden Surface Reaction Intermediate in Single-Nanoparticle Catalysis

et al. 2014

View full text Add to dashboard Cite

Detecting and characterizing reaction intermediates is not only important and powerful for elucidating reaction mechanisms but also challenging in general because of the low populations of intermediates in a reaction mixture. Studying surface reaction intermediates in heterogeneous catalysis presents additional challenges, especially the ubiquitous structural heterogeneity among the catalyst particles and the accompanying polydispersion in reaction kinetics. Here we use single-molecule fluorescence microscopy to study two complementary types of Au nanocatalystsmesoporous-silica-coated Au nanorods (i.e., Au@mSiO 2 nanorods) and bare 5.3 nm pseudospherical Au nanoparticlesat the single-particle, singleturnover resolution in catalyzing the oxidative deacetylation of amplex red by H 2 O 2 , a synthetically relevant and increasingly important probe reaction. For both nanocatalysts, the distributions of the microscopic reaction time from a single catalyst particle clearly reveal a kinetic intermediate, which is hidden when the data are averaged over many particles or only the time-averaged turnover rates are examined for a single particle. This intermediate is further resolvable by single-turnover kinetics at the subparticle level. Detailed single-molecule kinetic analysis leads to a quantitative reaction mechanism and supports that the intermediate is likely a surface-adsorbed one-electron-oxidized amplex red radical. The quantitation of kinetic parameters further allows for the evaluation of the large reactivity inhomogeneity among the individual nanorods and pseudospherical nanoparticles, and for Au@mSiO 2 nanorods, it uncovers their size-dependent reactivity in catalyzing the first one-electron oxidation of amplex red to the radical. Such single-particle, single-molecule kinetic studies are expected to be broadly useful for dissecting reaction kinetics and mechanisms.

show abstract

Electrochemistry and Optical Microscopy

Kanoufi

2021

Encyclopedia of Electrochemistry

View full text Add to dashboard Cite

Electrochemistry exploits local current heterogeneities at various scales ranging from the micrometer to the nanometer. The last decade has witnessed unprecedented progress in the development of a wide range of electroanalytical techniques allowing to reveal and quantify such heterogeneity through multiscale and multifonctionnal operando probing of electrochemical processes. However most of these advanced electrochemical imaging techniques, employing scanning probes, suffer from either low imaging throughput or limited imaging size. In parallel, optical microscopies, which can image a wide field of view in a single snapshot, have made considerable progress in terms of sensitivity, resolution and implementation of detection modes. Optical microscopies are then mature enough to propose, with basic bench equipment, to probe in a non destructive way a wide range of optical (and therefore structural) properties of a material in situ, in real time: under operating conditions. They offer promising alternative strategies for quantitative high-resolution imaging of electrochemistry. The first sections recall the optical properties of materials and how they can be probed optically. They discuss fluorescence, Raman, surface plasmon resonance, scattering or refractive index. Then the different optical microscopes used to image electrochemical processes are examined along with some strategies to extract quantitative electrochemical information from optical images. Finally the last section reviews some examples of in situ imaging, at micro-to nanometer resolution, and quantification of electrochemical processes ranging from solution diffusion to the conversion of molecular interfaces or solids.]

show abstract

Identification of a Critical Intermediate in Galvanic Exchange Reactions by Single‐Nanoparticle‐Resolved Kinetics

Cited by 67 publications

References 33 publications

Ex Situ and in Situ Surface Plasmon Monitoring of Temperature-Dependent Structural Evolution in Galvanic Replacement Reactions at a Single-Particle Level

Ex Situ and in Situ Surface Plasmon Monitoring of Temperature-Dependent Structural Evolution in Galvanic Replacement Reactions at a Single-Particle Level

Single-Molecule Kinetics Reveals a Hidden Surface Reaction Intermediate in Single-Nanoparticle Catalysis

Electrochemistry and Optical Microscopy

Contact Info

Product

Resources

About