Dispersion of colloidal TiO2 nanoparticles on mesoporous materials targeting photocatalysis applications

Crystallization of well-defined anatase nanoparticles in SBA-15 for the photocatalytic decomposition of acetic acid

“…The size (5 nm) of the anatase nanoparticles derived from TEM image and UV-vis absorption spectra and the consistent between the decrease of the pore volume of SBA-15 and the TiO 2 content together with the SEM observation that no observation of anatase particles in SEM image conrmed the formation of the anatase nanoparticles in the mesopores (6 nm) of the SBA-15. The size, the band gap energy and the sharpness of the reported anatase particles prepared in SBA-15 [13][14][15][16][17][18][19][20][28][29][30][31][32][33][34][35][36][37] as well as their photocatalytic reactions are summarized in Table S1. † The sharpness for SBA-15-anatase hybrids were relatively narrow compared with the values derived from the reported UV-vis absorption spectra of the anatase particles prepared in SBA-15, conrmed the narrow particle distribution of the anatase particles.…”

Functionalization methods of SBA-15 mesoporous molecular sieve: a brief overview

“…This method is one of the most commonly used when the species to be inserted into the SBA-15 remain in cationic forms under acidic conditions, similar to those used in the synthesis of SBA-15, for example Ga and Al at acidic pH (~ 1) do not condense [42]. Another advantage in comparison to direct synthesis is the high percentage of impregnation of the components in the active sites, the values approach or even exceed the estimated theoretical percentage without destroying the support mesostructure [59][60][61]. Despite the mentioned advantages, the post synthesis method presents some drawbacks, such as: production of non-uniform materials due to evaporation process that leads to the migration of the material from the pores to the surface [58]; reduction of surface area, pore volume, pore diameter [25,[59][60][61]; dependence on the nature of the solvent to ensure adequate distribution and dispersion of the particles in the carrier [43]; and oxidation of transition metal oxides giving low heteroatom dispersion [62].…”

“…Thus, some changes in the synthesis methods have been made to overcome the drawbacks. TiO 2 /SBA-15 was obtained by altering the route of the direct synthesis method by introducing the TiO 2 nanoparticles on the SBA-15 synthesis gel before the silica source, this method called an anchor in situ (ISA) by the authors [61,90]. Li et al [10] reported a synthesis route with two templates for Al-Ce-SBA-15 to overcome the problem of metal agglomeration.…”

Microstructure of SiO2/TiO2 hybrid electrospun nanofibers and their application in dye degradation

“…Hence, the activity of such photocatalysts is mainly determined by their adsorption ability and the concentration of electrons and holes on their surface. Generally, higher specific surface area can endow photocatalysts with higher photocatalytic efficiency [9][10][11][12][13]. Sometimes, to obtain high surface area and adsorption capacity, more defective sites can be formed on the surface and in the bulk of photocatalysts.…”