XPS characterization of Mn2O3 nanomaterials functionalized with Ag and SnO2

X-ray photoelectron spectroscopy was used to characterize the chemical composition and elemental states of bare and composite Mn2O3 (Mn2O3-Ag, Mn2O3-SnO2) nanomaterials. The target systems were prepared by the initial plasma enhanced-chemical vapor deposition of manganese oxides on alumina substrates, followed by annealing in inert atmospheres and functionalization with Ag and SnO2 by radio frequency- sputtering on the Mn2O3 surface. The survey scans of the fabricated samples, along with detailed spectra of the C 1s, O 1s, Mn 2p, Mn 3s, and, eventually, Ag 3d, Ag MVV, and Sn 3d regions, were collected and analyzed in detail. The obtained results revealed the formation of composite systems characterized by the presence of Mn2O3 free from other manganese oxides and pure SnO2, whereas appreciable Ag oxidation was observed. The O 1s photoelectron peaks could be fitted by means of two components related to lattice oxygen and to hydroxyl groups/oxygen species chemisorbed on surface O defects. The occurrence of the latter could exert a beneficial effect on the system functional behavior in gas sensing and electrocatalytic applications.