Unraveling Ce³⁺ detection at the surface of ceria nanopowders by UPS analysis

Abstract

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...

Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials

“…According to the literature, the Ce 3d spectra can be interpreted by assuming a model of five spin–orbit coupled doublets (Ce 3d 5/2 and Ce 3d 3/2 ): two for Ce 3+ oxidation states and three for Ce 4+ oxidation states (labeled in Figure a as V0–U0 and V1–U1 and as V–U, V2–U2, and V3–U3, respectively). These complex features have their origin in the hybridization of Ce 4f with O 2p binding orbitals and the partial occupation of the orbitals in the 4f valence state, giving rise to a well-known “shake-up” process, with some reports depicting 6–10 characteristic peaks. , In this way, our results confirm the presence of the Ce 4+ and Ce 3+ oxidation states in all studied samples. The amounts of Ce 4+ and Ce 3+ , corresponding to the [CeO 8 ] and [CeO 8 ·V o i ] clusters, respectively, can be correlated with the U3 peak derived from the transition between the 4f 0 initial and final states.…”

“…These complex features have their origin in the hybridization of Ce 4f with O 2p binding orbitals and the partial occupation of the orbitals in the 4f valence state, giving rise to a well-known "shake-up" process, with some reports depicting 6−10 characteristic peaks. 66,67 In this way, our results confirm the presence of the Ce 4+ and Ce 3+ oxidation states in all studied samples. The amounts of Ce 4+ and Ce 3+ , corresponding to the [CeO 8 ] and [CeO 8 •V o i ] clusters, respectively, can be correlated with the U3 peak derived from the transition between the 4f 0 initial and final states.…”

The Extent of Platinum-Induced Hydrogen Spillover on Cerium Dioxide

“…35−37 For XPS on CeO 2 surfaces, unwanted X-ray effects are often seen in the formation of Ce 3+ due to beam-induced defect formation. 38,39 Definite exclusion of radiation effects is generally not possible. In the present study, evolution of the XPS peaks was measured in a time-resolved manner.…”

“…The Ce M-edge spectra for both regions of the sample are depicted in Figure c. It has to be noted that X-ray spectroscopy runs the risk of inducing radiation artifacts into the studied sample. − For XPS on CeO 2 surfaces, unwanted X-ray effects are often seen in the formation of Ce 3+ due to beam-induced defect formation. , Definite exclusion of radiation effects is generally not possible. In the present study, evolution of the XPS peaks was measured in a time-resolved manner.…”

Phase Relationship and Ni Solubility in Nanoparticles of Ce0.9Zr0.1O2

“…We observed the same phenomenon in our previous work on (Ce 0.9 Zr 0.1 ) 1-x Co x O 2-δ samples with x = 0.05 and 0.03 annealed at 600 °C. [49] The decrease of N values for the coordination shells of CZ5 and CZ3 samples annealed at 600 °C might be a result of Ni being in very small particles of NiO with a large ratio of under-coordinated superficial atoms respect to the fully coordinated bulk atoms, as predicted by Kuzmin and Chaboy. [53] The analysis of the EXAFS data completes a systematic characterization of Ni-Ce 0.9 Zr 0.1 O 2 samples prepared by the citrate method, with the aim to determine the location and…”