Ultrafast Elemental and Oxidation-State Mapping of Hematite by 4D Electron Microscopy

We describe a new methodology that sheds light on the fundamental electronic processes that occur at the subsurface regions of inorganic solid photocatalysts. Three distinct kinds of microscopic imaging are used that yield spatial, temporal, and energy-resolved information. We also carefully conside...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society Vol. 139; no. 13; pp. 4916 - 4922
Main Authors: Su, Zixue, Baskin, J Spencer, Zhou, Wuzong, Thomas, John M, Zewail, Ahmed H
Format: Journal Article
Language:English
Published: United States 05.04.2017
ISSN:1520-5126
Online Access:Get more information
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We describe a new methodology that sheds light on the fundamental electronic processes that occur at the subsurface regions of inorganic solid photocatalysts. Three distinct kinds of microscopic imaging are used that yield spatial, temporal, and energy-resolved information. We also carefully consider the effect of photon-induced near-field electron microscopy (PINEM), first reported by Zewail et al. in 2009. The value of this methodology is illustrated by studying afresh a popular and viable photocatalyst, hematite, α-Fe O that exhibits most of the properties required in a practical application. By employing high-energy electron-loss signals (of several hundred eV), coupled to femtosecond temporal resolution as well as ultrafast energy-filtered transmission electron microscopy in 4D, we have, inter alia, identified Fe ions that have a lifetime of a few picoseconds, as well as associated photoinduced electronic transitions and charge transfer processes.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1520-5126
DOI:10.1021/jacs.7b00906