Quantum tunneling between two plasmonic resonators links nonlinear quantum optics with terahertz nanoelectronics. We describe the direct observation of and control over plasmon resonances at length scales in range 0.4 to 1.3 nanometers across molecular tunnel junctions made bridged by self-assembled monolayers (SAMs). The barrier width height are controlled properties molecules. Using electron energy-loss spectroscopy, we directly observe a mode, charge transfer plasmon, whose frequency...

Galvanic replacement (GR) is a simple and widely used approach to synthesize hollow nanostructures for applications in catalysis, plasmonics, biomedical research. The reaction driven by the difference electrochemical potential between two metals solution. However, transient stages of this are not fully understood. Here, we show using liquid cell transmission electron microscopy that silver (Ag) nanocubes become via nucleation, growth, coalescence voids inside nanocubes, as they undergo GR...

Fabrication and synthesis of plasmonic structures is rapidly moving towards sub-nanometer accuracy in control over shape inter-particle distance. This holds the promise for developing device components based on novel, non-classical electro-optical effects. Monochromated electron energy-loss spectroscopy (EELS) has recent years demonstrated its value as a qualitative experimental technique nano-optics due to unprecedented spatial resolution. Here, we demonstrate that EELS can also be used...

ConspectusHierarchically organized nanoparticles (NPs) possess unique properties and are relevant to various technological applications. An important "bottom-up" strategy for building such hierarchical nanostructures is guide the individual NPs into ordered nanoarchitectures using intermolecular interactions external forces. However, our current understanding of nanoscale that govern self-assembly processes usually relies on post-synthesis/assembly or indirect characterization. Theoretical...

Lithography provides the precision to pattern large arrays of metallic nanostructures with varying geometries, enabling systematic studies and discoveries new phenomena in plasmonics. However, surface plasmon resonances experience more damping lithographically–defined structures than chemically–synthesized nanoparticles comparable geometries. Grain boundaries, roughness, substrate effects adhesion layers have been reported as causes damping, but it is difficult isolate these effects. Using...

Liquid cell transmission electron microscopy has become a powerful and increasingly accessible technique for in situ studies of nanoscale processes liquid solution phase. Exploring reaction mechanisms electrochemical or crystal growth requires precise control over experimental conditions, with temperature being one the most critical factors. Here we carry out series experiments simulations at different temperatures well-studied system Ag nanocrystal driven by changes redox environment caused...

Nanoparticle (NP) self-assembly has been recognized as an important technological process for forming ordered nanostructures. However, the detailed dynamics of assembly processes remain poorly understood. Using in situ liquid cell transmission electron microscopy, we describe modes gold (Au) nanorods (NRs) solution mediated by hydrogen bonding between NR-bound cysteamine linker molecules. Our observations reveal that tuning concentration, two different NR can be achieved. These proceed via...

One-pot wet-chemical synthesis is a simple way to obtain nanoparticles (NPs) with well-defined shape and composition. However, achieving good control over NP would require comprehensive understanding of the mechanisms formation, something that challenging experimentally. Here, we study formation gold (Au) core–palladium (Pd) shell NPs under kinetically thermodynamically controlled reaction conditions using in situ liquid cell transmission electron microscopy (TEM). By controlling...

Abstract At elevated temperatures, bimetallic nanomaterials change their morphologies because of the interdiffusion atomic species, which also alters properties. The Kirkendall effect (KE) is a well-known phenomenon associated with such interdiffusion. Here, we show how KE can manifest in nanoparticles (NPs) by following core–shell NPs Au and Pd during heat treatment situ transmission electron microscopy. Unlike monometallic NPs, these did not evolve into hollow core NPs. Instead, nanoscale...

We study the galvanic replacement reaction of silver nanocubes in dilute, aqueous ethylenediaminetetraacetic acid disodium salt (EDTA)-capped gold aurate solutions using situ liquid-cell electron microscopy. Au/Ag etched nanostructures with concave faces are formed via (1) etching that starts from nanocubes, followed by (2) deposition an Au layer as a result replacement, and (3) particle coalescence monomer attachment where small nanoparticles during radiolysis. Analysis Ag removal rate...

We study the overgrowth process of silver-on-gold nanocubes in dilute, aqueous silver nitrate solution presence a reducing agent, ascorbic acid, using situ liquid-cell electron microscopy. Au–Ag core–shell nanostructures were formed via two mechanistic pathways: (1) nuclei coalescence, where Ag nanoparticles absorbed onto Au nanocubes, and (2) monomer attachment, atoms epitaxially deposited nanocubes. Both pathways lead to same nanostructures. Analysis deposition rate reveals growth modes...

We can learn about the interactions between nanoparticles (NPs) in solution and solid surfaces by tracking how they move. Here, we use liquid cell transmission electron microscopy (TEM) to follow directly translation rotation of Au nanobipyramids (NBPs) nanorods (NRs) adsorbed onto a SiNx surface at rate 300 frames per second. This study is motivated enduring need for detailed description NP motion on this common TEM. will show that NPs move intermittently time scales milliseconds. First,...

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Self-assembly of solvated nanoparticles (NPs) is governed by numerous competing interactions. However, relatively little known about the time-dependent mechanisms through which these interactions enable and guide nanoparticle self-assembly process. Here, using in situ transmission electron microscopy imaging combined with atomistic modeling, it shown that forces governing hydrophobic change shapes. By comparing how gold nanospheres, nanocubes, nanorods, nanobipyramids assemble, strength...

Abstract The catalytic performance of bimetallic nanoparticles (NPs) strongly depends on their structural and compositional changes under reaction conditions. At the fundamental level, these are driven by redox reactions that occur surface NPs. degree complexity in is further amplified NPs because both metals can have own with reactant molecules, addition to any synergistic effects between metal nanocatalysts reducible oxides. Here, gas phase oxidation reduction reactions, carbon monoxide...

Both chemical and electrochemical etching are effective methods for tailoring the surface composition of Pt-based catalytic bimetallic nanoparticles (NPs). However, detailed nanoscale mechanisms, which needed achieving fine control over etch processes, still not understood. Here, we study selective Ni Pt-Ni rhombic dodecahedron NPs using in situ liquid-phase transmission electron microscopy. Our real-time observations show that intermediate NP structures evolve differently two cases....

Abstract The combination of imaging with electrochemical quantification in liquid cell transmission electron microscopy (TEM) provides opportunities for visualizing material processes good spatial and temporal resolution a way that is inaccessible bench‐top experiments. electrode used TEM determines the reliability consistency measurements also influences when on electrode. Here, arising from use 2D materials electrochemistry are explored. Through modeling, it demonstrated graphene...

Quantum plasmon resonances have been recently observed across molecular tunnel junctions. The present work extends these studies theoretically using a generalized space-charge corrected electromagnetic model for wider range of molecules.

The combination of electrochemical analysis, temperature control and <italic>in situ</italic> TEM imaging directly probes the etching Ni from bimetallic Ni–Pt nanoparticles.

Understanding the electrode materials’ surface is of fundamental importance for catalytic studies as most electrochemical reactions take place there. Although several operando techniques have been used to monitor electrocatalytic process, real‐time imaging observing change on materials are still a challenge and limited few stable systems. Herein, quasi‐in situ transmission electron microscopy (TEM) was carried out track morphological local structure evolution during oxygen reduction reaction...

Supported nonprecious metal catalysts such as copper (Cu) are promising replacements for Pt-based a wide range of energy-related electrochemical reactions. Direct deposition is one the most straightforward and versatile methods to synthesize supported catalysts. However, further advancement in design requires detailed mechanistic understanding interplay between kinetics thermodynamics phenomena under realistic reaction conditions. Here, we study electrodeposition Cu on carbon nanotubes...

We study the degradation process of closely spaced silver and gold nanocubes under high-energy electron beam irradiation using transmission microscopy (TEM). The high aspect ratio gaps between degraded in many cases as a result protrusion filament formation during irradiation. demonstrate that molecular coating nanoparticles can act protective barrier to minimize electron-beam-induced damage on passivated nanoparticles.

Abstract Fe anodes are emerging as cost‐effective components in long duration storage applications, with a benefit being the high natural abundance of Fe. Additive and electrode design have advanced performance electrodes, but more precise understanding formation process failure mechanisms is important for continued optimization. These interfacial electrochemical processes, which involve short‐lived intermediate species, require analysis spatial temporal resolution to provide full picture....