Self-assembled laminated nanoribbon-directed synthesis of noble metallic nanoparticle-decorated silica nanotubes and their catalytic applications

Substrate-supported noble metallic nanoparticles have received intense attention owing to their great potential in various applications. In this work, silica nanotube-supported metallic nanoparticles (i.e., Au, Ag, and Pd) are synthesized by in situ reducing metal ions into nanoparticles on the nanotube surface. The silica nanotubes are prepared through the traditional sol-gel approach using laminated nanoribbons as soft templates, which are self-assembled from dipeptide-amphiphiles. The surface of silica nanotubes is functionalized to display amino groups, which serve as active sites to host metallic particles. By changing the preparation conditions, the wall thickness of silica nanotubes is adjusted and the density of metallic nanoparticles on silica surface is facilely tuned. Finally the metallic nanoparticle-coated silica nanotubes are proven to be applicable in recyclable catalysis of 4-nitrophenol (4-NP) reduction.