The template preparation and characterization of three new shapes of titania nanometer-array systems

A two-step anodization process was used to prepare highly ordered porous anodic alumina template (PAA). The template method was combined with the sol-electrophoresis deposition and sol-gel method to synthesize three types of nanometer-array systems. The titania nano-arrays have a high specific surface area. The sol-gel template method was also applied to prepare the rod-shaped titania nanowire-arrays. The diameter of titania nanometer-array is about 50 nm; the length is about 20 μm; and the distance of neighboring two nanowires is about 100 nm. Through controlling the pore depth of the template, the membrane with periodical modulating titania nanodots was prepared. The diameter of the nanodots on the membrane surface was about 75 nm and the dot distance was about 100 nm. Also a compact structure has been found on the back face of the membrane. The sol-electrophoresis template method was used to prepare the nanowire-array system with the shape of string of candied haws. The diameter of nanowires was about 75 nm and the length was about 20 μm. The periodic concave-convex structures were found in each nanowire and the shape looked like string of candied haws. The three types of nano-array systems have a high specific surface area. It can be predicted that this type of surface modulating array system will have new properties and effects that are different from those of common membranes, nanodots and nanowires.