2023/04/17 by E. Tzomos, Mikko-Heikki Mikkelä, M.-H. Mikkelä +4 · 2 citations
Chemistry · Materials Science · #Analytical Chemistry (journal) #Atomic physics #Binding energy #Catalytic Processes in Materials Science #Chemical physics #Chemistry #Copper-based nanomaterials and applications #Inorganic chemistry #Materials science #Metal #Nanoparticle #Nanotechnology #Nuclear magnetic resonance #Oxidation state #Oxide #Physics #Spectral line #X-ray photoelectron spectroscopy #ZnO doping and properties
paper · pdf · doi:10.1016/j.susc.2023.122307
openalex publication_date 2023/04/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Over decades the Ag 3d-level binding energy has been puzzling researchers with its unusual sign and value in silver oxides. For the absolute majority of metals, the metal-to-oxide binding energy shifts are positive and depend significantly on the oxidation state, while in Ag-oxides the oxide shift was time after time reported negative, small, and close for the two very different Ag(I) and Ag(III) oxidation states. In the current work, a photoelectron spectroscopy (PES) investigation on the in-situ created free nanoparticles simultaneously containing both metallic silver and silver-oxide parts provided the grounds to reconsider the old consensus on the Ag-oxide shifts. The Ag 3d energies for the metallic and the oxide parts established in the current experimental work allowed estimating a ≈ 1.2 eV positive shift for the realized oxidation state. This estimate was made possible by using a beam of free nanoparticles with finely controlled composition. The PES experiments on such a beam allowed for a continuous and fast renewal of the poorly conducting sample and for a reliable and accurate calibration relative to vacuum. The constant oxide shift observed at several different oxidation conditions, as well as the relatively narrow and symmetric oxide peaks, point to one dominating oxidation state being present in the particles.
