Photocatalytic reaction characteristics of the titanium dioxide supported on the long phosphorescent phosphor by a low pressure chemical vapor deposition.
This study investigated the photocatalytic behavior of titanium dioxide (TiO2)-supported on the long phosphorescent materials. Nanocrystalline TiO2 was directly deposited on the plate of alkaline earth aluminate phosphor, CaAl2O4: Eu2+, Nd3+ by a low pressure chemical vapor deposition (LPCVD). Photocatalytic reaction performance was examined with the decomposition of benzene gas by using a gas chromatography (GC) system under ultraviolet and visible light (λ > 410 nm) irradiations. The LPCVD TiO2-coated phosphors showed active photocatalytic reaction under visible irradiation. The mechanism of the photocatalytic reactivity for the TiO,-coated phosphorescent phosphor was discussed in terms of the energy band structure and phosphorescence. The coupling of TiO2 with phosphor may result in energy band bending in the junction region, which makes the TiO, crystal at the interface to be photo-reactive under visible light irradiation. The fastest degradation of ben- zene gas occurred for the TiO,-coated phosphor prepared with 1 min deposition time (-150 nm thickness). The LPCVD TiO,-coated phosphor is also photo-reactive under darkness through the light photons emitted from the CaAl2O4 phosphor. In addition, the TiO2-coated phosphorescent phosphors were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Jung-Sik
JS
Kim
Seung-Woo
SW
Kim
Sang-Chul
SC
Jung
D001554:Benzene / Q000737:chemistry; D002384:Catalysis; D008163:Luminescent Measurements; D055668:Photochemical Processes; D011312:Pressure; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
C009495:titanium dioxide; D014025:Titanium; D001554:Benzene