Unraveling Ce detection at the surface of ceria nanopowders by UPS analysis

A sequential analysis using Ultra-violet Photoelectron Spectroscopy (UPS) and X-ray Photoelectron Spectroscopy (XPS) on ceria nanopowders has been implemented to identify the influence of the X-ray beam on the surface of this oxide. For the first time, UPS analysis evidenced the photoreductive effec...

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Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2022-09, Vol.24 (37), p.22815-22822
Main Authors: Cardenas, Luis, Molinet-Chinaglia, Clément, Loridant, Stéphane
Format: Article
Language:English
Online Access:Get full text
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Summary:A sequential analysis using Ultra-violet Photoelectron Spectroscopy (UPS) and X-ray Photoelectron Spectroscopy (XPS) on ceria nanopowders has been implemented to identify the influence of the X-ray beam on the surface of this oxide. For the first time, UPS analysis evidenced the photoreductive effect of XPS analysis on ceria after an oxidative in situ pretreatment, leading to an overestimation of the Ce 3+ /Ce 4+ ratio obtained by XPS. Based on this spectroscopy methodology, UPS imposes itself as a leading technique for analyzing powders with minimal impact on the authentic chemical state, thus paving the way for identifying the real ratio of Ce 4+ and Ce 3+ of ceria after oxidative and reductive in situ treatments. A novel and controlled methodology combining UPS/XPS spectroscopies intended to determine the electronic state at the surface of ceria nanopowders.
ISSN:1463-9076
1463-9084
DOI:10.1039/d2cp02736d