which the byproducts (EtOH and H2O molecules) were unable
to diffuse into the relatively nonpolar solvent pentanol in a
timely manner and were trapped inside the newly formed
nanowires. With several washings, the spaces occupied by these
encapsulated small byproducts became the hollow parts of the
nanowires. The rough surfaces of the HSiNWs also indicated
that they were not formed by slow thermodynamically
controlled processes. In contrast, the condensation rate
probably decreased at a high molar ratio of a NH4OH aqueous
solution to TEOS because of the large excess of NH4OH and
the H2O introduced at the same time. Therefore, no byproduct
or PVP−H2O mixture was trapped inside the nanomaterials
(Figure 4C−F). The observation of solid nanowires, nanorods,
and nanoparticles at high molar ratio of NH4OH to TEOS was
consistent with Kuijk et al.’s report.32 The formation of such
long HSiNWs was quite challenging, and the one-pot process
reported herein is not only novel but also facile and reliable.