The
apparent reaction rate constants increased with
increasing dip-coating cycles, which is attributed to the increase in the amount of TiO2 available to
participate in the photocatalytic reaction. However,
the apparent reaction rate constants decreased
when the number of dip-coating cycles
exceeded 15 which mainly results from the following
two factors: (1) increase in opacity and light
scattering of thick TiO2 films, leading to a decrease
in the passage of irradiation through the film, and
(2) TiO2 films partly breaking off with an increase
in dip-coating cycles, causing a decrease in the
amount of TiO2 available to participate in the