Nanocasting a mesoporous palladium replica from a body-centered cubic mesoporous silica and palladium and silver metallic nanoarchitectures within mesoporous channels

Abstract

In this study we employed a facile impregnation method—based on the application of capillary forces, evaporation of solvent and subsequent thermal reduction under H₂—for the synthesis of various metal/mesoporous silica composites. Using this approach we obtained highly dispersed Ag nanoparticles within BCC (body-centered cubic) mesoporous silica, interconnected Pd networks within the BCC mesoporous silica, and Ag and Pd nanowires within hexagonal cylindrical channels, all of which we characterized using small-angle X-ray scattering, transmission electron microscopy, N₂ sorption isotherms, and powder X-ray diffraction. Notably, this paper reports the first example of such a Pd metal replica structure prepared through use of the unique BCC-type mesoporous silica as a hard template and subsequent etching in HF_(aq). Finally, we report the successful fabrication of a highly disperse Ag/silica complex prepared through a convenient one-step synthesis.