Preparation And Characterization Of Highly Ordered Nano-porous Materials

Highly ordered nanomaterials are currently under great attention. Templated synthesis is a very efficient and well controlled synthetic route. Anodic aluminium oxide (AAO) is one of the most widely used templates. Based on our previous research on AAO, the highly ordered patterns formed on alumina surfaces during the anodic oxidization processes were investigated. Highly ordered AAO provided good template for the synthesis and assembly of nanowires. Further, we extended our anodic oxidization to titanium and have successfully produced porous T1O2 films. By controlling the surface morphology and surface chemistry, the wettability of the TiO₂ films can be switched between super-hydrophobic and super-hydrophilic states.The main results are as below:1. Ordered surface patterns were observed during the oxidation of aluminium. It is proposed that they were formed due to a non-equilibrium reaction-diffusion mechanism.2. Highly ordered AAO were produced using a double anodic strategy, and free-standing AAO were successfully obtained using an optimized electrochemical etching processes. Various nanowires were prepared using the AAO as templates. Multi-layered nanowires were prepared using double-pulsed electrochemical deposition methods. Gold nanowires show angle-dependent scattering effect under dark-field microscopy.3. The anodic oxidation method was successfully applied to prepare porous TiO₂ films. By controlling the anodic condition, TiO₂ films with different surface morphology were produced. Combining surface chemical modification, the TiO₂ films show tuneable wettability, which could be adjusted between super-hydrophobic and super-hydrophilic states. Our results showed that the porous TiO₂ films have potential applications in the fields like antifogging, self-cleanning and solar cells.