Titania nanotube/hollow sphere hybrid material: Dual-template synthesis and photocatalytic property

Inspired by the complicated structure of natural substances, we designed and fabricated nanotube/hollow sphere hybrid structured functional anatase titania material. Cellulosic substance (commercial filter paper) was chosen as nanotube template while silica and polystyrene colloidal microspheres with different diameters were employed as hollow sphere templates. The ultrathin nature of titania layer enabled faithful replication of the nanoscopic structural details of both the template substances. The microsphere and cellulose templates were removed by calcination for polystyrene microsphere template case, and further alkali treatment was carried out to dissolve away the silica component for silica microsphere template case. The obtained anatase titania nanotubes were decorated with nanoscale titania hollow spheres with wall thickness of about 7.5 nm. The resulted hybrid materials exhibited similar but superior photocatalytic efficiency compared with simple titania nanotube structured materials due to the higher surface area endowed by the complex highly porous structure.