Abstract:
The TiO
2/SiO
2 composites were prepared with different mass fractions of precursor (
w (TiO
2)=0, 2.6%, 4.0%, 5.5%, 7.0% and 8.6%) by impregnation method, and using
Broussonetia papyrifear leaves as biological template and silicon source and tetrabutyltitanate (TBOT) as precursor. The composite materials were characterized by XRD, FTIR, SEM, XPS, TEM, BET, XRF, UV−Vis DRS, etc. The results showed that the TiO
2/SiO
2 composites mainly consisted of anatase phase TiO
2, and forming nanospheres with an average particle size of 500 nm.The composite posseses typical mesopore structure with an average pore size of 7.2 nm and a specific surface area of 50.42 m
2/g. The photocatalytic degradation experiments were carried out to evaluate the photocatalytic activity and kinetics of the materials under UV light irradiation using rhodamine B as the research object. The results show that compared with
w(TiO
2)=0 catalyst, the TiO
2/SiO
2 materials prepared by changing the mass fraction of TiO
2 show strong photocatalytic activity, and the catalyst doped
w(TiO
2)=5.5% shows the best catalytic effect. The kinetic study shows that the UV photocatalytic degradation of rhodamine B conforms to the characteristics of quasi first order reaction in the presence of different catalytic materials. Under ultraviolet light for 90 min at room temperature, the rhodamine B solution was almost completely degraded by the
w(TiO
2)=5.5% catalyst, and the apparent rate constant
k reached the maximum value of 0.0911 min
−1, 21.69 times that of
w(TiO
2)=0 catalyst.