Unusual Changes in Electronic Band-Edge Energies of the Nanostructured Transparent n-Type Semiconductor Zr-Doped Anatase TiO₂ (Ti_1–xZr_xO₂; x < 0.3)

Abstract

By the establishment of highly controllable synthetic routes, electronic band-edge energies of the n-type transparent semiconductor Zr-doped anatase TiO2 have been studied holistically for the first time up to 30 atom % Zr, employing powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen gas sorption measurements, UV/vis spectroscopies, and Mott-Schottky measurements. The materials were produced through a sol-gel synthetic procedure that ensures good compositional homogeneity of the materials, while introducing nanoporosity in the structure, by achieving a mild calcination condition. Vegard's law was discovered among the homogeneous samples, and correlations were established between the chemical compositions and optical and electronic properties of the materials. Up to 20% Zr doping, the optical energy gap increases to 3.29 eV (vs 3.19 eV for TiO2), and the absolute conduction band-edge energy increases to -3.90 eV (vs -4.14 eV). The energy changes of the conduction band edge are more drastic than what is expected from the average electronegativities of the compounds, which may be due to the unnatural coordination environment around Zr in the anatase phase.

High-Efficient Elimination of Spiramycin by Fe3O4/ZSM-5/Sch via Heterogeneous Photo-Fenton Oxidation at Neutral pH

“…The conduction band (CB) and valence band (VB) energies were calculated as described in reference [21]. The specific calculation method can be found in the Supplementary Materials.…”

Influence of the photodeposition sequence on the photocatalytic activity of plasmonic Ag–Au/TiO2 nanocomposites

“…9,10 To overcome these impediments, numerous strategies have been employed so far including metal and non-metal doping as well as functionalizing the TiO 2 surface. [11][12][13][14][15][16][17] In recent years, the deposition of noble metal nanoparticles (e.g., Au, Ag, Pd and Pt) on TiO 2 has acquired strong attention for providing means to increase both, solar light absorption in the visible range and electron-hole pair separation which both result in increased photocatalytic activity. [18][19][20][21][22] These metal nanoparticles introduce extra energy levels into the wide band gap of TiO 2 that affect the charge transfer properties.…”