Preparation and Characterization of Bi3+-TiO2 and its Photocatalytic Activity

Photocatalytic partial oxidation of methanol to methyl formate under visible light irradiation on Bi-doped TiO2 via tuning band structure and surface hydroxyls

Preparing visible light responsive catalysts for partial oxidation of methanol to methyl formate is a challenging issue. This work addresses the synthesis, characterization and theoretical calculation of Bi doped TiO₂ catalysts as well as their photocatalytic performance and reaction mechanism for MF synthesis from methanol. The catalysts were prepared by a simple wet chemical method. The results of the characterization and theoretical calculation evidenced that bismuth was intercalated in the lattice of anatase by the substitution of titanium. Impurity levels were formed in the valence band, conduction band and between the two bands. The Bi 6s and 5p orbitals contributed to the formation of the impurity levels. The photo-excited electrons transited from the valence band via impurity levels, formed by Bi 6s orbitals, to the conduction band. The doping of Bi enhanced surface hydroxyls, reduced the band gaps and raised the valence band edges (VBE) of the Bi doped catalyst. The Bi doped catalysts were visible light responsive due to the reduced band gap. The surface hydroxyls were beneficial to the methanol conversion, and the rise of the VBE enhanced the redox potential of the photogenerated holes. Only moderate redox potentials and sufficient surface hydroxyls could lead to high methanol conversion and MF selectivity. This study is of great significance to the development of the photocatalytic synthesis theory and provides a green route for MF synthesis from methanol.

Bi-doped titania is well studied for photocatalytic partial oxidation of methanol to methyl formate under visible light irradiation.

A new nano-photocatalyst based on Pt and Bi co-doped TiO2 for efficient visible-light photo degradation of amoxicillin

Herein, the photo degradation of amoxicillin (AMX) was thoroughly investigated using Pt and Bi co-doped TiO₂ photocatalysts under visible-light irradiation.

Visible light-induced photocatalytic activity of modified titanium(iv) oxide with zero-valent bismuth clusters

Surface modification of TiO₂ with zero-valent Bi nanoclusters induces high photocatalytic activity under visible light.

Ti powder-assisted synthesis of Ti3+ self-doped TiO2 nanosheets with enhanced visible-light photoactivity

Visible-light responsive Ti³⁺ self-doped TiO₂ nanosheets with exposed high-energy (001) facets were fabricated using Ti powder as a reductant.

New approach toward nanosized ferrous ferric oxide and Fe(3)O(4)-doped titanium dioxide photocatalysts

In this article, ferrous ferric oxide and Fe(3)O(4)-doped titanium dioxide have been synthesized by a low-temperature sol-gel process. In particular, we studied the structural characteristics of newly synthesized photosensitive catalysts and their photocatalytic abilities under UV and visible light irradiation. The elemental composition, surface area, crystallinity, and morphology of synthesized catalysts were characterized by Fourier transformation infrared spectrophotometry, X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy with selected area electron diffraction and energy-dispersive X-ray spectroscopy. The UV-vis transmission, zeta-potential, and cytotoxicity of the synthesized catalysts are also discussed. It is anticipated that the synthesized ferrous ferric oxide arrays a prospective photocatalyst substitute for titanium dioxide.

(Bi, C and N) codoped TiO2 nanoparticles

Bi, C and N codoped TiO2 photocatalysts were prepared by doping TiO2 with BiCl3 and KSCN in a sol-gel process (denoted as (Bi,SCN)-TiO2). The catalyst samples were then characterized by XRD, TEM, diffuse reflectance spectra (DRS), XPS, FT-IR and N2 sorption. Bi, C and N elements were detected both by XPS and elemental analysis, while S element was not found, suggesting that SCN- group may have decomposed during the sol-gel process. The effects of the doping on the properties and photocatalytic activity of the TiO2 were investigated. It was found that the cation and the anion affected the properties of TiO2 differently. The optical absorption onset of TiO2 red shifted in the presence of Bi3+, while long tail occurred in the presence of SCN-. The order of photoreactivity for TiO2 samples was as follow: (Bi,SCN)-TiO2>Bi-TiO2>undoped TiO2>p25 TiO2, whatever under UV or visible light illumination. The high photoreactivity of the doped TiO2 was also discussed.