The growth mechanism for silicon oxide nanowires synthesized from an Au nanoparticle/polyimide/Si thin film stack

The catalytic effect of Pt nanoparticles supported on silicon oxide nanowire

3.5 nm sized Pt nanocatalysts supported on silicon oxide nanowires (SiO(X)NWs) were fabricated by decorating the SiO(X)NWs with Pt nanoparticles using a simple physical deposition system without any surface pretreatment. High curvature of the nanowire surface together with the weak metal-substrate interaction helped to maintain discrete particle morphology with spherical shapes during deposition. Catalytic efficiency of the SiO(X)NWs coated with Pt nanoparticles was demonstrated through reduction of methylene blue in the presence of sodium borohydride. It was demonstrated that the highly curved nanowire surface allowed the Pt nanoparticles to be loaded with increased particle density, providing a larger surface area for the catalytic reaction. It was also shown that a simple heat treatment in vacuum improves the effectiveness of the Pt nanoparticles as a catalyst without loss of catalytic activity when used repeatedly. We expect that this metal nanoparticle-decorated nanowire can be easily extended to other heterogeneous reactions and can also be used as a template for building three-dimensional hierarchical nanostructures.

Hierarchical nanostructure generated by decorating SiO(x) nanowires with CoPt nanoparticles

Silicon oxide nanowires were decorated with magnetically hard 3-5 nm-sized CoPt nanoparticles using a simple physical deposition system without any pretreatment of the nanowire surface. High curvature of the nanowire surface together with the weak metal-substrate interaction helped to maintain discrete particle morphology with spherical shapes during deposition. The weak interaction also allowed the preferential nucleation of the deposited film on the pre-existing particles so that the film deposition can be repeated in order to increase the particle size without significantly altering the particle morphology. We expect that this method can be easily extended to create other metal nanoparticle-decorated nanowires.