Identification of bulk and surface sulfur impurities in TiO2 by synchrotron x-ray absorption near edge structure

Abstract

Synchrotron x-ray absorption near edge structure (XANES) measurements of Ti and S K edges, combined with first principles simulations, are used to characterize S-doped TiO2 prepared by oxidative annealing of TiS2 at various temperatures. Ti-edge XANES and x-ray powder diffraction data indicate that samples annealed above 300°C have an anatase TiO2 crystal structure with no trace of TiS2 domains. S-edge XANES data reveal that the local structure seen by S atoms evolves gradually, from TiS2 to a qualitatively different structure, as the annealing temperature is increased from 200to500°C. For samples annealed at 500°C, the spectrum appears to have features that can be assigned to S on the surface in the form of SO4 and S defects in the bulk (most likely S interstitials) of TiO2.

Identification of Mn Site in BaTiO3by Synchrotron X-Ray Absorption Spectroscopy Measurements

“…In addition, the EXAFS measurement allows the identification of the nearest neighboring atoms to the absorbing atom to determine the coordination environment for the metal of interest [26]. Recently, both techniques have been successfully applied to various classes of materials to obtain their local structures [27][28][29][30][31][32][33][34][35]. Our previous experimental and theoretical works on applying the XAS techniques to determine the local structure of PZT-based materials have already been established [36][37][38].…”

Sulfur-Doped TiO2: Structure and Surface Properties

“…Indeed, sulfur-doped TiO 2 has attracted much attention due to the fact that increasing quantities of S can reduce the band gap [23], as well as show a strong absorption in the visible light [24]. or could be embedded within the TiO 2 lattice, thus creating S-Ti-O bonds [31].…”

2D Metal Organic Framework Nanosheet: A Universal Platform Promoting Highly Efficient Visible‐Light‐Induced Hydrogen Production

“…The latter is capable of detecting the chemical state of atoms both at the surface and in the bulk. [53] To further study the electronic coupling between CdS and 2D NMF, DFT based calculations were conducted. The work functions () of CdS and 2D NMF were calculated to be 4.68 and 4.90 eV, respectively (Figure 4a and b).…”