Pore-Engineered Silica Nanoreactors for Chemical Interaction-Guided Confined Synthesis of Porous Platinum Nanodendrites

Designing and synthesizing noble metal nano structures with tunable porosity and nanoscopic intricacies is crucial for highly augmented surface properties and as gateway to the wide range of applications. Here, we develop a pore engineered nanoreactor (PENR)-based approach toward the synthesis of porous platinum nanodendrites (PtNDs) of yolk-in-shell and shell-in-shell morphologies and with tunable nanoscale porosity. In our strategy, first, various silica-based PENRs with variable porosity and each containing a single Au seed were synthesized by a successive base-catalyzed condensation reaction of a mixture of aminoalkyl-organosilanes in a one-pot reverse-microemulsion strategy, followed by selective silica hydrolysis reactions. The key strategy involved the addition of different silanes at different stages of silica condensation, rendering appropriately located fragile and rigid silica regions in silica nanospheres, which were conveniently carved into a termite-nest like structure with amine-rich nanocompartments. Further, growth of different PtNDs was chemically guided by metallophilic amine groups through the pores and channels of nanoreactors, and overall morphologies of PtNDs were highly customizable by the different confined nanospaces inside PENRs.