Fabrication of centimeter-sized sphere of mesoporous silica with well-defined hollow nanosphere topology and its high performance in adsorbing phenylalanine

Large mesoporous silica spheres with centimeter-scale were synthesized for the first time via a multi-level self-assembly using an emulsion system of ethyl ether, tetraethyl orthosilicate (TEOS) and cetyltrimethylammonium bromide (CTAB) surfactant. Apart from the controllable morphology and size, the inorganic hybrid or organic functionalized self-molding mesoporous materials could also be synthesized through one-pot method, that is, the synthesis and functionalization and self-molding with special morphology of the mesoporous material were realized simultaneously. According to the analysis of SEM, TEM, XRD and N2 adsorption–desorption, the obtained macroscopic spheres were composed of nanosized silica spheres, which possessed relatively ordered mesostructure. Moreover, the obtained macroscopic silica spheres could resist a pressure of 46 N cm−2. The adsorption of phenylalanine was performed to assess the performance of these macrospheres, in which the adsorption capacity of aminopropyl triethoxysilane (APTES) functionalized sample was up to 196 mg g−1, twice higher than the best value reported in the literature.