Preparation and characterization of mesostructured titanium dioxide and its application as a photocatalyst for the wastewater treatment

Mesostructured Titanium Dioxide (Ti-TMS1, Ti-TMS2) was firstly synthesized with different length chain alkylphosphate and alkylamine surfactants as templates. The templates can be successfully removed by reflux in the EtOH/H2O/KOH solution instead of calcination. The powder X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images confirm that these materials are the hexagonal array of Ti-TMS with different pore sized from about 27 to 44 Angstrom. The length of the hydrocarbon tail of alkylphosphate can be used to vary the pore size of Ti-TMS. Moreover, increasing the length of the hydrocarbon tail of alkylphosphate will lead to improve the structure and uniformity of TMS. The uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of Ti-TMS1 prepared using dodecylphosphate and hexadecylphosphate as templates. After removal of the templates, the mesostructure of the sample (Ti-TMS1) templated by alkylphosphate surfactant was preserved to a greater degree than that of the sample (Ti-TMS2) templated by alkylamine surfactant. Several other factors on the form of the structure and removal of the template were discussed. The photocatalytic activity of Ti-TMS was also investigated by using 2,4,6-trichlorophenol (TCP) solution as a model wastewater. It was found that the photocatalytic degradation of TCP over Ti-TMS occur-red at a much faster rate than that over TiO2 nanoparticles. (C) 1999 Elsevier Science S.A. All rights reserved.