Role of cetyltrimethyl ammonium bromide on sol–gel preparation of porous cerium titanate photocatalyst

Cetyltrimethyl ammonium bromide (CTAB) was used as template agent to prepare porous cerium titanate by sol–gel method. Besides major brannerite CeTi 2 O 6 in monoclinic system, the addition of CTAB template leads to formation of minor anatase TiO 2 and CeO 2 phases. FT-Far-IR spectra also prove Ce-O and Ti-O-Ti bonds in the porous cerium titanate. The addition of CTAB template in the precursor can obviously enlarge BET surface area and pore volume of cerium titanate. Removal of CTAB template during calcination leaves mesoporous structure in the cerium titanate samples, which are presented in the N 2 adsorption-desorption isotherms. Not only more hydroxyl radicals can be produced on the samples obtained using CTAB, but also photocatalytic oxidation efficiency is strongly influenced by the variation of CTAB amount. The reaction rate constant is 2.44 × 10 −2 min -1 on the porous cerium titanate sample obtained using 2 g CTAB, while the reaction rate constant is only 9.60 × 10 −3 min -1 on the sample without CTAB. UV-Visible spectra of ofloxacin solution during photocatalytic oxidation demonstrate the degradation of typical organic groups in ofloxacin molecule. CTAB was used as template agent to prepare porous cerium titanate by sol–gel method. CTAB can introduce porous structure and enhance surface area of the samples. More hydroxyl radicals can be produced on the samples using CTAB as template. Photocatalytic oxidation efficiency is strongly affected by the variation of CTAB dosage.