Mesoporous Molecular Sieve Preparation, Characterization And Application

It's known that mesoporous molecular sieves (MMS) are characteristic of orderly channels, plenty of surface hydroxyls and various morphologies. Orderly channels in MMS provide a class of low-cost templates for use in the synthesis of one-dimensional (1D) structures. Generally, this method involves three steps, i.e. infiltration of the pores with an appropriate precursor via a vapor- or solution-based approach, conversion of the precursor to the desired materials, and recovery of the 1D nanostructures by selective removal of the template. In fact, due to the negative effect, originating from diffusive obstruction in the small pores and adsorption function of the exterior surface, it has been difficult to achieve complete filling with high yield of the desired materials. Therefore, much effort is needed to improve the performance of nanocasting in the channels of MMS. It has been reported that metal nanowires can be obtained on the surface of a physical template, on which active functionalities reside in array, e.g. hydroxyls, carbonyls, carboxyls and ethers etc.. These active functionalities coordinate with metal ions, facilitating the formation of metal nanowires. It's expected that controllable synthesis of 1D structures can be achieved on the surface of MMS, by selecting appropriate reactants and solvent, due to their abundant surface hydroxyls and variable surface morphologies.In this manuscript, three kinds of.Si-based MMS (MCM-41, MCM-48, SBA-15), organic hybridization MMS and metal ion-containing MMS have been prepared. The synthesized MMS have been characterized by XRD, N₂ adsorption-desorption isotherms, IR and SEM measurements. It has been found that vanadium, which can form polyanions and condense, can form well-orderly V-containing MCM-48 easily, with the molar ratio of 0.4 of CTAB/SiO₂.The applications of MMS in the region of inorganic nano-synthesis have been explored. Nanorods, notubes, nanorings and nanocrystals of GaN have been prepared, respectively, via the reaction of GaCl₃ with NaN₃ at 260-300℃ in benzene solution. Nanofibers and nanocrystals of GaN have been synthesized, respectively, via the reaction of GaCl₃ with Li₃N at 260-300℃ through benzenethermal route. In both of...