Post-synthesis of TiO(2) Dispersed Inside the Pore Channels of SBA-15 and its Photocatalytic Activity for the Degradation of Methylene Blue

• Published in: INTERNATIONAL JOURNAL OF THE SOCIETY OF MATERIALS ENGINEERING FOR RESOURCES 2011-06, Vol.18 (1), p.11-17
• Main Authors: Shindo, Takayoshi, Koizumi, Naoto, Hatakeyama, Koki, Ikeuchi, Takao
• Format: Article
• Language: English
• Subjects: Channels; Degradation; Dispersion; Photocatalysis; Surface chemistry; Titanium; Titanium dioxide; Titanium oxides
• ISSN: 1347-9725

TiO(2)-SBA-15 mesoporous materials in which titanium oxide species were dispersed inside the pore channels of SBA-15 were prepared by a novel post-synthesis method. In this method, cetyltrimethylammonium bromide surfactant molecules were incorporated inside the channels of the mesopores of SBA-15 followed by the addition of titanium tetraethoxide. Effect of hydrolysis conditions of titanium tetraethoxide on the formation and properties of Ti oxides in TiO(2)-SBA-15 materials was investigated. Physico-chemical properties of TiO(2)-SBA-15 materials were characterized by XRD, N(2) adsorption, SEM and UV-vis. Size and morphology of Ti oxide species in TiO(2)-SBA-15 materials were dependent on the hydrolysis conditions of titanium tetraethoxide, i.e., H(2)O/Ti molar ratio. Dispersed titanium oxide species were mainly formed on the internal surface of SBA-15, i.e., on the surface of mesopore walls of the TiO(2)-SBA-15 samples when synthesized at low H(2)O/Ti ratios of 2 and 4, whereas large TiO(2) anatase particles were predominantly formed on the external surface of SBA-15 when the samples were prepared at high H(2)O/Ti molar ratios. The photocatalytic activity of the TiO(2)-SBA-15 samples was investigated for the degradation of methylene blue, MB, and compared with that of pure TiO(2), P25. The TiO(2)-SBA-15 samples, in which titanium oxide species were dispersed on the internal surface of SBA-15, showed higher and more stable photocatalytic activity in the degradation and/or decolorization of MB than P25 and TiO(2)-SBA-15 which has TiO(2) particles on the outer surface of SBA-15.