Visualizing Progressive Atomic Change in the Metal Surface Structure Made by Ultrafast Electronic Interactions in an Ambient Environment

Abstract

Understanding the atomic and molecular phenomena occurring in working catalysts and nanodevices requires the elucidation of atomic migration originating from electronic excitations.The progressive atomic dynamics on metal surface under controlled electronic stimulus in real time,space,and gas environments are visualizedf or the first time.B yi nsitu environmental transmission electron microscopy, the gas molecules introduced into the biased metal nanogap could be activated by electron tunneling and caused the unpredicted atomic dynamics.T he typically inactive gold was oxidized locally on the positive tip and field-evaporated to the negative tip,r esulting in the atomic reconstruction on the negative tip surface.T his finding of at unneling-electron-attached-gas process will bring new insights into the design of nanostructures such as nanoparticle catalysts and quantum nanodots and will stimulate syntheses of novel nanomaterials not seen in the ambient environment.

Electrochemistry under confinement

“…A well-known problem for nanogap production is the so called electric migration, where metal atoms of the nanogap electrode migrate in the electric field in line with the flowing current, leading to a merging event of the confining walls. 136 Naitoh et al used electronic migration to form 2 nm gaps between Au electrodes. 130 They observed the gap shrinkage by measuring the transferred current between both electrodes as conductivity strongly increases with decreasing electrode distance.…”

Direct Observation of Heterogeneous Surface Reactivity and Reconstruction on Terminations of Grain Boundaries of Platinum

“…Despite those remarkable advances, however, direct observation of surface reactivity and structural reconstruction on terminations of GBs remains a forbidden challenge, which is crucial for the GBs engineering in catalysis. With a state-of-the-art spatial resolution, in situ aberration-corrected transmission electron microscopy (AC-TEM) has shown the power for studies of nanocrystal growth, , nanoparticles (NPs) restructuring under gas environments, ,− catalysis, ,− and so on.…”

Atomic-scale ETEM Observation of Chemical Reactions on the Surface of Nanomaterials

“…We have investigated atomic structures and dynamics of nanomaterials under reaction conditions by ETEM while taking into account the effects of electron irradiation [2][3][4][5][6][7]. We have found that the surface of Pt nanoparticles is oxidized in O2 gas under electron irradiation ( Figure 1).…”