Electron Microscopy Characterization of Silicon Dioxide Nanotubes

Abstract

AbstractWell‐developed crystals of [Pt(NH3)4](HCO3)2 are employed as template for the synthesis of silicon dioxide nanotubes (SiO2‐NTs). Silicon dioxide, which is produced by a sol‐gel reaction, coats the surface of these crystals and builds up the nanotube walls. In the final step, the Pt‐salt fibers are thermally decomposed and auto‐reduced to metallic Pt nanoparticles. Scanning and transmission electron microscopy (SEM and TEM) investigations of the product confirm the formation of silicon dioxide nanotubes in high yield. The tube walls consist of amorphous silicon dioxide. The tube length generally is 0.5 — 3 μm, while the thickness varies in two distinct ranges: thick tubes have a diameter of 100 — 500 nm and thin ones of approximately 50 nm. Most of the NTs are filled with Pt particles, but others, typically the larger ones with open tube ends, obviously are empty. Presumably, open ends cause the observed Pt loss. In closed SiO2‐NTs, Pt forms as ca. 10 nm large particles in the tube core and as 1 — 2 nm large particles inside the tube walls.