X-ray photoelectron spectroscopy of transition metal ions attached to the surface of rod-shape anatase TiO2 nanocrystals

Abstract

X-ray photoelectron spectra were obtained for a series of M-TiO 2 samples in which transition metal ions are directly attached to the surface of anatase TiO 2 nanocrystals. The samples were prepared using CrCl 3 .nH 2 O, MnCl 2 .nH 2 O, FeCl 2 .nH 2 O, CoCl 2 .nH 2 O, NiCl 2 .nH 2 O, and CuCl 2 .nH 2 O as metal sources. We observed spontaneous air oxidation of the metal for the Mn-TiO 2 and Fe-TiO 2 samples as indicated by rapid color changes. X-ray photoelectron spectroscopy (XPS) data confirms the oxidation states of the metals Cr, Co, and Ni are unchanged from the precursor, Mn and Fe are oxidized, and Cu is in a more reduced state. The reduction of Cu likely arises during the XPS experimenta phenomenon well-documented in the literature; whereas UV-visible data of the Cu-TiO 2 dispersions are consistent with Cu 2+ .

Diffusion doping of cobalt in rod-shape anatase TiO2 nanocrystals leads to antiferromagnetism

“…In our previous XPS studies of Co (surface) -TiO 2 and M,M 0 (surface) -TiO 2 we observed Co 2p 3/2 binding energies of 780.5-780.9 eV. 37,43 Based on the new XPS data, it is apparent that the Co 2p 3/2 binding energy for Co (doped) -TiO 2 is approximately 1 eV larger than for Co (surface) -TiO 2 . Choudhury et al report binding energies of 781.4 eV and 797.2 eV for Co 2p 3/2 and 2p 1/2 electrons from XPS study of Co 2+ doped TiO 2 nanoparticles.…”

Development of Non-Enzymatic Glucose Biosensors Based on Electrochemically Prepared Polypyrrole-Chitosan-Titanium Dioxide Nanocomposite Films

“…It has been discussed that the ratio between the two peaks can be correlated to the surface area of the material [30]. In Figure 1 (e), the titanium atom shows two distinct peaks at 458.4 eV for the Ti2p1/2 and at 459.2 eV for the Ti2p3/2 showing the clear evidence of the element present in the surface of the Ppy-CS-TiO2 nanocomposite films [31]. FE-SEM micrographs confirmed the homogeneous distribution of TiO2 at the surface of the Ppy-CS-TiO2 nanocomposites films in Figure 2 (a), which shows the white dots in colour of the nanoparticles of TiO2.…”

Visible-light-driven catalytic degradation of ciprofloxacin on metal (Fe, Co, Ni) doped titanate nanotubes synthesized by one-pot approach

“…species and the feature at 712.57 eV may be able to attribute to Fe 3? [31][32][33][34][35]. The XPS peak at 717.57 eV may be attributed to the satellite Fe 2?…”