High Resolution XPS Study of a Thin CoO(111) Film Grown on Co(0001)

Abstract

Transition metal oxides are often used as the active components in heterogenous catalysis. Therefore the investigation of single crystal oxides as model systems is important to understand the reaction mechanisms on a microscopic level. The reactivity of a ͑111͒ surface of ionic rocksalt type structures seems to be rather high as has been established for NiO͑111͒. The ideal ͑111͒ surface is polar, and thus unstable, which means that stabilization mechanisms must exist. Here, high resolution XPS measurements of a thin epitaxial CoO͑111͒ film grown on CO͑0001͒ by exposing the surface to Ϸ10000 L O 2 are reported.

Fabrication and electrochemical behavior of flower-like ZnO–CoO–C nanowall arrays as anodes for lithium-ion batteries

“…Co 2p spectrum (Fig. 4a) displays the Co 2p3/2 and Co 2p1/2 peaks at 780.1 and 796.6 eV, respectively, which can be assigned to Co atom of CoO phase [22][23][24]. In addition, Raman spectra of ZnO-CoO-C shows the vibration modes of ZnO at 334, 442, and 583 cm −1 ; CoO at 463, 503 and 644 cm −1 , and carbon at 1383 and 1608 cm −1 [20,25].…”

Training-induced inversion of spontaneous exchange bias field on La1.5Ca0.5CoMnO6

“…It has been largely reported in the literature that the expected binding energies for Co 3+ and Co 2+ are located at 779.5 and 780.5 eV, respectively 26 . Noteworthy, depending on the cation symmetry one may observe intense satellite features related to Co 2+ at octahedral sites, in contrast to Co 3+ at octahedral or Co 2+ at tetrahedral sites 27 .…”

Pulsed-laser-ablation based nanodecoration of multi-wall-carbon nanotubes by Co–Ni nanoparticles for dye-sensitized solar cell counter electrode applications

“…Conversely, the O1 s spectra can be deconvoluted into two different components located at *529.8 and 531.9 eV. The main peak located at BE 529.8 eV confirms the presence of metal oxygen bonds (i.e., Ni-O [42] and Co-O [43]), while the less prominent one (at 531.9 eV) corresponds to the O-H bonds of the surface hydroxyl groups [44]. All these results confirm that the outer surface of the Co-Ni NPs is oxidized.…”