| en |
Incorporation of chitosan and glass substrate for improvement in adsorption, separation, and stability of TiO2 photodegradation
Amir, M. N. I.; Julkapli, N. M. & Abd Hamid, S. B.
Abstract
It is demonstrated that single titanium dioxide
(TiO2) has high potential for photodegradation of pollutants.
However, it is still far from becoming an effective
photocatalyst system, due to issues of adsorption process,
separation, as well as dissolution. Therefore, this study
highlights the high adsorption capacity, simplified separation,
and the promising stability of TiO2(SY) (synthesized
via sol–gel method) photocatalyst, fabricated using chitosan–
TiO2(SY) and supported by glass substrate (Cs–
TiO2(SY)/glass substrate) photocatalysts. Chitosan (Cs),
with abundant –R–NH and NH2 groups, promotes the
adsorption sites of methyl orange (MO) and OH groups for
major attachment to TiO2(SY). Meanwhile, the glass substrate
increases stability and assists separation of the photocatalysts.
Initially, nano-TiO2(SY) has been characterized
using high-resolution transmission electron microscope.
Cs–TiO2(SY)/glass substrate was fabricated via dip-coating.
The distribution and interface between the photocatalytic
components were characterized by Fourier transform
infrared absorption spectroscopy, UV–Vis diffuse reflectance
spectroscopy, field emission scanning electron
microscopy, and energy-dispersive spectrometer. UV–Vis
analysis of the multilayer photocatalyst (2, 4, 6, and 8
layers) was further carried out by the adsorption–photodegradation,
with MO as model of pollutant. Seventy
percent of the total removal of MO via optimized eight
layers of photocatalyst was achieved within 1 h of UV
irradiation. The adsorption photocatalyst achieved 50 %
with no exposure to UV light for 15 min of irradiation. It is
concluded that suitable photocatalytic conditions and
sample parameters possessing the multilayer photocatalyst
of Cs–TiO2(SY) are beneficial toward the adsorption–photodegradation
process in wastewater treatment.
Keywords
Adsorption–photodegradation; Methyl orange; Titanium dioxide; Chitosan; Glass substrate
|
