Cardenas Luis, Molinet-Chinaglia Clément, Loridant Stéphane
Univ Lyon, Université Claude Bernard-Lyon 1, CNRS, IRCELYON-UMR 5256, 2 av. A. Einstein, F-69626 Villeurbanne Cedex, France.
Phys Chem Chem Phys. 2022 Sep 28;24(37):22815-22822. doi: 10.1039/d2cp02736d.
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 pretreatment, leading to an overestimation of the Ce/Ce 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 and Ce of ceria after oxidative and reductive treatments.