Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5361621 | Applied Surface Science | 2009 | 4 Pages |
Abstract
Ni-doped InTaO4 nanocrystallites were synthesized by a reactive pulsed laser ablation process, aiming at visible-light-operating photocatalysts. The third harmonics beam of a Nd:YAG laser was focused onto a sintered In0.9Ni0.1TaO4âδ target in mixture background gases (O2 + He). The deposited species were columnar-structured porous films consisting of primary nanocrystallites. The mean diameter of the primary nanocrystallites was 4 nm. Optical absorption characteristics, especially in low absorbance (sub-band) regions, were evaluated by photoacoustic spectroscopy. Absorption in the sub-band region decreased drastically with increasing O2 partial pressures. It is inferred that oxygen deficiencies are suppressed, because of enough oxygen vapors in the reactive background gases. An absorption band around 420 nm appeared obviously in O2 partial pressures above 5%, in the Ni-doped InTaO4 nanocrystallites. The visible region absorption band is presumably attributed to the Ni 3d-eg orbitals. In contrast, pure InTaO4 nanocrystallites showed a sharp band edge, without the visible absorption band.
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Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Takehito Yoshida, Hirokazu Toyoyama, Ikurou Umezu, Akira Sugimura,