| Summary: | TiO2 nanotubes and immobilized TiO2 nanotubes were successfully
synthesized by a hydrothermal method and binding method. The produced
photocatalysts were characterized by the Brunauer-Emmett-Teller (BET) method,
scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX),
transmission electron microscope (TEM) and X-ray diffraction (XRD). The
photocatalytic activities of the photocatalysts were evaluated through the
photocatalytic degradation of aqueous phenol solution in a batch reactor. TiO2
nanotubes produced at 130 °C for 3 h showed the highest degradation rate of phenol
compared with the other samples prepared at 130 °C for 1 h, 5 h and 7 h, complete
degradation being achieved in 130 min. Special focus was given in order to
determine the optimum composition of each component (catalyst, support and binder)
in the immobilization of TiO2 nanotubes. The highest efficiency of phenol
degradation was achieved when the ratios of TiO2 nanotubes: silica gel: colloidal
silica was 1:2:20. For the comparison, TiO2 nanotubes and immobilized TiO2
nanotubes showed higher photocatalytic activity as compared with pure TiO2. The
photocatalytic performance of TiO2 nanotubes and immobilized TiO2 nanotubes
achieved 100 % and 98.0 % respectively, of phenol degradation, whereas pure TiO2
attained only 77.0 % degradation. The photocatalytic activity of the immobilized
TiO2 nanotubes was slightly decreased after four cycles for phenol degradation.
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