Enhanced photophysical properties of nanopatterned titania nanodots/nanowires upon hybridization with silica via block copolymer templated sol-gel process

We fabricated titanium dioxide (TiO₂)-silica (SiO₂) nanocomposite structures with controlled morphology by a simple synthetic approach using cooperative sol-gel chemistry and block copolymer (BCP) self-assembly. Mixed TiO₂-SiO₂ sol-gel precursors were blended with amphiphilic poly(styrene-block-ethylene oxide) (PS-b-PEO) BCPs where the precursors were selectively incorporated into the hydrophilic PEO domains. Changing the volumetric ratio of TiO₂-SiO₂ sol-gel precursor from 5% to 20%, a stepwise structural inversion occurred from nanodot arrays to discrete nanowires. Template free hybrid inorganic nanostructures were produced after the removal of PS-b-PEO by irradiation of UV light. The morphological evolution and photophysical properties were investigated by microscopic studies, UV-visible absorption and photocatalytic properties.