TY - JOUR
T1 - Structure characterization and tuning of perovskite-like NaTaO3 for applications in photoluminescence and photocatalysis
AU - Hu, Che Chia
AU - Tsai, Chien Cheng
AU - Teng, Hsisheng
PY - 2009/2/1
Y1 - 2009/2/1
N2 - Perovskite-like NaTaO3 powders have potential applications in photoluminescence and photocatalysis. Sol-gel, hydrothermal and solid-state methods were used to synthesize NaTaO3 powders of different crystalline structures, which were identified by Rietveld refinement simulation of X-ray diffraction patterns and transmission electron microscopic diffraction. The refinement results show that the sol-gel specimen has a monoclinic phase with a Ta-O-Ta bond angle of 179° while the hydrothermal and solid-state specimens have an orthorhombic phase with bond angles of 163° and 157°, respectively. By excitation with a 304 nm light source, these NaTaO3 specimens show photoluminescence emission at ca. 450 nm. The photoluminescence intensity of the specimens had an order solid state >hydrothermal >sol-gel, which is opposite to that of the Ta-O-Ta bond angle. On the other hand, the photocatalytic activity of the NaTaO3 specimens in water splitting showed the same order as that of the Ta-O-Ta bond angle. This paper directly evidenced that the Ta-O-Ta bond angle affects the separation rate of the photo-induced charges, as well as that structure tuning of tantalates is achievable and crucial for applications in photoluminescence and photocatalysis.
AB - Perovskite-like NaTaO3 powders have potential applications in photoluminescence and photocatalysis. Sol-gel, hydrothermal and solid-state methods were used to synthesize NaTaO3 powders of different crystalline structures, which were identified by Rietveld refinement simulation of X-ray diffraction patterns and transmission electron microscopic diffraction. The refinement results show that the sol-gel specimen has a monoclinic phase with a Ta-O-Ta bond angle of 179° while the hydrothermal and solid-state specimens have an orthorhombic phase with bond angles of 163° and 157°, respectively. By excitation with a 304 nm light source, these NaTaO3 specimens show photoluminescence emission at ca. 450 nm. The photoluminescence intensity of the specimens had an order solid state >hydrothermal >sol-gel, which is opposite to that of the Ta-O-Ta bond angle. On the other hand, the photocatalytic activity of the NaTaO3 specimens in water splitting showed the same order as that of the Ta-O-Ta bond angle. This paper directly evidenced that the Ta-O-Ta bond angle affects the separation rate of the photo-induced charges, as well as that structure tuning of tantalates is achievable and crucial for applications in photoluminescence and photocatalysis.
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U2 - 10.1111/j.1551-2916.2008.02869.x
DO - 10.1111/j.1551-2916.2008.02869.x
M3 - Article
AN - SCOPUS:60849126106
VL - 92
SP - 460
EP - 466
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
SN - 0002-7820
IS - 2
ER -