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Correlating activities and defects in (photo)electrocatalysts using in-situ multi-modal microscopic imaging.

Accepted version
Peer-reviewed

Type

Article

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Abstract

Photo(electro)catalysts use sunlight to drive chemical reactions such as water splitting. A major factor limiting photocatalyst development is physicochemical heterogeneity which leads to spatially dependent reactivity. To link structure and function in such systems, simultaneous probing of the electrochemical environment at microscopic length scales and a broad range of timescales (ns to s) is required. Here, we address this challenge by developing and applying in-situ (optical) microscopies to map and correlate local electrochemical activity, with hole lifetimes, oxygen vacancy concentrations and photoelectrode crystal structure. Using this multi-modal approach, we study prototypical hematite (α-Fe2O3) photoelectrodes. We demonstrate that regions of α-Fe2O3, adjacent to microstructural cracks have a better photoelectrochemical response and reduced back electron recombination due to an optimal oxygen vacancy concentration, with the film thickness and extended light exposure also influencing local activity. Our work highlights the importance of microscopic mapping to understand activity, in even seemingly homogeneous photoelectrodes.

Description

Keywords

40 Engineering, 34 Chemical Sciences, 3406 Physical Chemistry, 1 Underpinning research, 1.1 Normal biological development and functioning

Journal Title

Nat Commun

Conference Name

Journal ISSN

2041-1723
2041-1723

Volume Title

Publisher

Springer Science and Business Media LLC
Sponsorship
Engineering and Physical Sciences Research Council (EP/S030638/1)
EPSRC (EP/V055127/1)
Engineering and Physical Sciences Research Council (EP/M006360/1)
Engineering and Physical Sciences Research Council (EP/L015978/1)
EPSRC (EP/W017091/1)