IR spectroscopic investigation of the particle size and morphology of platinum nanoparticles supported on mesoporous silicate

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

“…The general steps involve: the functionalization of the previously prepared support (for example SBA-15) in the pores/surface by the insertion of organic groups; solubilization of the precursor source of the metal; mixing the functionalized support with the solution containing the precursor source of the metal to promote the interaction of the opposites between the functionalized groups and the metal cation followed by washing, drying, calcination and reduction [14,48]. The literature reports the preparation of Ag/SBA-15 [51], Pt/SBA-15 [14,48] and Au/SBA-15 [79] by the grafting method. In the case of Pt/SBA-15, SBA-15 support was pretreated in water for 1 h under reflux, followed by heating at 150 °C under vacuum.…”

“…In brief, the method involves the following steps: choosing a suitable dendrimer to interact with the solution of the precursor source of the metal; mixing the solutions of the precursor source of the metal and source of the dendrimer; reduction of the metal by the NaBH 4 reducing agent; immobilization of the nanoparticles in the support by ultrasound; separation of nanoparticles followed by drying. The separation step is by centrifugation or evaporation system [14,[50][51][52][53]. Scheme 3 shows the main steps colloid immobilization (CI) and nanoparticles encapsulation (NE) methods, respectively.…”

“…Despite of the interest of the scientific community and researches accomplished, the functionalization of SBA-15 is challenging task because the heteroatoms can be introduced into the silica wall by replacing Si 4+ , within the mesopores or on the outer surface and modify the original properties of the support [15]. Literature report several methods of SBA-15 functionalization such as: direct synthesis or "one pot" procedure [25,[38][39][40][41], wetness impregnation [40,[42][43][44], deposition-precipitation (DP) [45][46][47], graft hybrid (GH) [48,49], colloid immobilization (CI) [50][51][52][53], nanoparticles encapsulation (NE) [54,55]. We briefly reviewed already mentioned methods of SBA-15 functionalization, because it is are the most reported in the literature, to verify if such methods are satisfactory or if we need of new functionalization method/strategies.…”