Abstract
The porous support supported TiO2 is considered to be the promising photocatalyst due to the fact that it is easily recovered from water and has high capacity to mineralize pollutants. Obviously, the expected structure of this kind of photocatalyst is egg-shell, that is, TiO2 is mainly on the external surface of the porous support. The reactivity of the supported photocatalyst strongly depends on the concentration of TiO2 on the external surface of the porous support. In this study, a kinetic model was developed to describe the effect of the external surface concentration of TiO2 (CESC) on the reactivity of egg-shell activated carbon (AC) supported TiO2 photocatalysts. It was found that the obtained model precisely described the effect of CESC, on the reactivity of TiO2/AC photocatalysts. This study can be used to deeply understand the performance of TiO2/AC catalysts and to provide valuable information on designing efficient supported TiO2 photocatalysts.
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Abbreviations
- R 1 :
-
concentration of the pollutant during degradation
- I :
-
illumination intensity
- K :
-
reaction rate constant
- s :
-
the surface area of a TiO2 particle
- a :
-
averaged absorption coefficient
- γ :
-
shape factor
- R :
-
dimension of the TiO2 particle
- I 0 :
-
illumination intensity reaching the wall of the photoreactor
- n :
-
number of TiO2 particles towards the lamp
- z :
-
thickness of the hybrid film of TiO2 and AC
- σ:
-
effective illuminated area of the TiO2 particle
- ϑ :
-
fraction of volume taken by TiO2 in the hybrid film of TiO2 and AC
- C ESC :
-
concentration of TiO2 in the hybrid film of TiO2 and AC
- D :
-
dimension of TiO2/AC particle
- H :
-
height of the photoreactor
- L :
-
radius of the photoreactor
- N :
-
number of TiO2/AC particle in the whole solution
- σ′ :
-
effective illumination area of TiO2/AC particle in the solution
- p p :
-
density of TiO2/AC particle
- C catalyst :
-
concentration of TiO2/AC in the solution
- k 1 :
-
true rate constant
- K′ :
-
adsorption constant
- k app :
-
apparent rate constant of pseudo-first order
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Zhang, X., Lei, L. A kinetic model for describing effect of the external surface concentration of TiO2 on the reactivity of eggshell activated carbon supported TiO2 photocatalyst. Chin. Sci. Bull. 52, 3339–3345 (2007). https://doi.org/10.1007/s11434-007-0497-1
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DOI: https://doi.org/10.1007/s11434-007-0497-1