A facile method to synthesize the photocatalytic TiO_2/montmorillonite nanocomposites with enhanced photoactivity

摘要

A new method for immobilizing nano-scaled TiO_2 on the surface of montmorillonite (Mt) clay has been developed. First, cationic surfactants were introduced into the Mt galleries through ion exchange and physical adsorption processes. Next a titanium precursor with negative charges was allowed to hydrolyze and condense around the nature clay to form meso-phase assemblies on the external and internal surface of the Mt. After the removal of the surfactant, a highly porous TiO_2 pillared clay with mesopores was formed. The cationic surfactant has a templating role, which not only tailored the formation of TiO_2 but also controlled the TiO_2 content in the composite. The photocatalytic performances of these new porous materials were evaluated by using methylene blue degradation. The photocatalytic activity of these TiO_2 composite is higher than that of P25 although TiO_2 only accounts for about one-third of the sample's mass in the composite samples.