The activity of the photocatalyst is mainly dependent on
the surface area, crystalline size, crystallinity and the support
structure. Firstly, the three-dimensionally interconnected pore
structures facilitate the diffusion of reactants and products from the active sites during the photocatalytic reaction, and a
higher surface area of composites provides a higher adsorption
capacity of reactive species[28], which increases the local
concentration of reactive species near active sites, and as a
result, improves the reaction rates. The degradation of
polluting molecules on the surface of photocatalyst is
achieved with the participation of photogenerated electrons
and holes, which are more likely to recombine at defect sites
on the surface of TiO2. Therefore, the photocatalytic efficiency
can be improved by suppressing the recombination rate of
photogenerated electrons and holes[29]. When TiO2 is coated on
MC, the formation of TiO2/MC hetero-junctions and excellent
electron conductivity of the carbon support facilitates the
transfer of photogenerated electrons from TiO2 to carbon
support, and reduces the recombination rate of electrons and
holes [30]. Moreover, the improved crystallinity of TiO2 with
less defect sites in MC could reduce the probability of the
recombination of electrons and holes. All these factors lead to
an improved activity of the TiO2/MC nanocomposites as
catalysts in the degradation of MO aqueous solution