TiO2 and then the anatase to rutile phase transformation occured
at high temperature. However, by using the same procedure and
introducing Si into TiO2 precursor solution, the nanowires in a
rutile phase with minor of anatase were produced directly. In this
case, it can be considered that the addition of Si into TiO2 matrix
could induce the nucleation and forming-ability in the rutile phase
rather than the anatase phase. Probably, by switching from TiO2
nanowires in anatase phase to rutile phase may have also contributed
to expansion of the diameter of nanowires.