Multifunctional mesoporous materials based on heterojunction titania-PB supported by SBA-15

Full text: Ordered mesoporous silica has been obtained through a surfactant-templated synthetic procedure in the step of hydrolysis using a silicon alkoxide. Mesoporous materials have an interesting pore structure and high surface area; therefore, these materials have interesting applications in several fields of chemistry as catalysts in the pore structure. The nonionic amphiphilic surfactant Pluoronic P123 has been used as a surfactant-template for preparation of the hexagonal mesoporous silica structures, a class of materials known as SBA-15 [1]. Prussian blue (PB) is a classical synthetic coordination compound of a dark blue color. PB, has a cubic framework and is also known as ferric hexacyanoferrate (II). The photodeposition of PB on semiconductor particles have attracted much attention, as a prominent method of preparing photocatalysts for various redox reactions. Titanium dioxide (TiO2) is a broadband semiconductor widely investigated in photocatalysis due to its high photoactivity, low toxicity, low cost and good thermal and chemical stability [2]. In this work, SBA-15 was obtained by the sol gel process from the acid hydrolysis of tetraethoxysilane (TEOS) under reflux conditions at 35ºC during 24 h. The incorporation of titanium in the SBA-15 network was prepared according to our previous work. The modification of surface of silica-titania nanoparticles with Prussian Blue was obtained by the photodeposition method reported by Tada et al. [3]. The prepared nanoparticles were characterized by nitrogen adsorption, X-ray fluorescence (XRF) and X-ray diffraction (XRD). The BET specific surface SBET, the total pore volume Vp, the mean pore size lP, and the pore size distribution (PSD) were estimated by the nitrogen adsorption data. [1] Da Silveira, T. et al. Micropor Mesopor Mat , V. 190, p. 227-233, 2014. [2] Pelaez., M. et al. Appl. Catal., B. V. 125, p. 331-349, 2012. [3] Tada, H. et al. J. Electrochem. Soc., V. 138, p. 140–144, 1991. (author)