Fabrication of Hierarchical Mesoporous TiO2 Nanowires Using Dual Templates

摘要

Titania (TiO2) having superior electrical, optical and catalytic properties has been widely exploited for diverse applications such as photovoltaic cells, gas sensors, heterogeneous photo and thermal catalysis, bandgap materials and photoelectrochromic devices.1,2 Especially mesoporous one-dimensional (1D) TiO2 has attracted intensive scientific interest because of its unique properties due to the confinement effects and large specific surface area. Common fabrication method for the 1D nanomaterials is the template-based synthesis,3,4,5 where porous membranes such as track-etched polycarbonate (PC), or anodic alumina) have been used as a template for growing the desired materials. When the precursor solution is introduced into the pores of the template, 1D nanostructure can be easily generated and its size can be controlled by the template pore sizes.6 In our work, hierarchical mesoporous TiO2 nanowires are prepared by adding the PS colloidal particles as another template into the porous PC membrane. The membrane containing colloidal particles is filled with the precursor solution including the block copolymers as structure-directing agents. Removing the colloidal particles and surfactants via calcination together with the membrane generates 1D nanowires with well-define mesopores with different sizes. Consequently, hierarchical mesoporous TiO2 nanowires were fabricated by the combination of sol-gel reaction and block copolymer self-assembly.