| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1330532 | Journal of Solid State Chemistry | 2011 | 7 Pages |
TiO2 photoelectrodes with various nanostructures have been successfully prepared by the anodization method. The morphology, microstructure and optical properties of as-prepared photoelectrodes were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet/visible light diffuse reflectance spectra (UV/vis/DRS), surface photovoltage spectroscopy (SPS) and photocurrent. The electronic structure and optical properties of La doped/undoped TiO2 photoelectrodes with different crystal structures were calculated by the density function theory. The photocatalytic and photoelectrocatalytic activities of as-prepared photoelectrodes were evaluated. The results showed that the anodization potentials played a crucial role in the surface morphology and microstructure. Both results of theoretical calculations and experimental tests demonstrated that La-doped photoelectrodes were more sensitive to light than undoped one. The difference of photoelectrodes performance was ascribed to the crystal configuration, impurity energy levels and long-range orientation moving of photogenerated carriers.
Graphical abstractPhotophysical chemistry processes in as-prepared TiO2 photoelectrodes. Overall scheme of TiO2 photoelectrodes: (A) movement of photoelectrons and holes without bias potentials; (B) movement of photoelectrons and holes at applied bias potentials; (a) and (b) were the transmission of photogenerated electrons and holes of local enlargement of (A) (black open circle): (a) photoelectrons movement in P-TiO2 photoelectrodes and La-TiO2 photoelectrodes, the red dot line denotes the top of valence band (VB) and the bottom of conduction band (CB) of pure photoelectrodes; (b) photoelectrons movement in P-160 and La-160 TiO2 photoelectrodes (mixed crystal phase). The number refers to as follows: (1) transmission process of photoelectrons and holes; (2) recombination process of photoelectrons and holes. Arrows represent the moving direction of photoelectrons.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Morphology and structure of La-doped photoelectrodes. ► Band gap and electric structure of La-doped and undoped photoelectrodes. ► Optical, PECH, PC and PEC properties of La-TiO2 photoelectrodes. ► Transmission process of photoelectron–hole pairs in La-TiO2 photoelectrodes.
