3.6 Photocatalytic kinetics of TiO2/MC samples
It is well known that decomposition of MO in water by
UV/TiO2 can be adequately described by a first-order kinetic
model. Therefore, the apparent rate constant was chosen as the
basic kinetic parameter for an activity comparison of the
different photocatalysts [31].
The apparent first-order kinetic equation ln(C0/C) = kt
was used to fit experimental data, where k is apparent rate
constant, C is the MO concentration in solution phase, and C0
is the initial concentration at t=30 min as catalysts reached
adsorption equilibrium after 30 min [32]. Fig. 8 showed kinetic
curves of the nanocomposites with different calcination
temperatures for the degradation of MO under UV irradiation.
The linear transform in ln(C0/C) as a function of
irradiation time confirms the apparent first-order reaction
kinetic characteristic. The slope of lnC0/C versus time plot
gives the value for the rate constant k as listed in Table 3. Such