ISSN:
1573-4854
Keywords:
porous TiO2
;
photoluminescence
;
EPR
;
adsorption of molecules
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The influence of adsorbed water, oxygen, air and vacuum on the photoluminescence (PL) and electron paramagnetic resonance (EPR) has been investigated in situ and quasi in situ for por-TiO2 (anatase). The broad PL signal in the visible spectral region decreases with increasing partial pressure of oxygen and vanishes at pressures higher than 1 mbar. Adsorption of water leads (i) to a fast quenching and (ii) to a subsequent increase of the PL signal. The concentration of the O2 −, O−, O3 − anion-radicals depends sensitively on the surface conditioning and on the illumination of the por-TiO2. Ti3+ centers could be observed only in vacuum treated samples. The concentrations of the Ti3+ and oxygen anion radicals are in the range of 1015 and 1017 cm−3, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009699324013
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