Synthesis of Highly Crystalline Hollow TiO2 Fibers Using Atomic Layer Deposition on Polymer Templates

A novel approach is applied to fabricate highly crystalline hollow TiO2 fibers with a uniform wall thickness. In this approach, first the polymer fibers of similar to 240 nm in diameter were synthesized by the electro-spinning technique as sacrificial templates. Second, TiO2 shell layers of similar to 75 nm in thickness were deposited on these templates using the atomic layer deposition technique. After the selective removal of polymer templates by suitable heat treatments (>500 degrees C), highly crystalline hollow TiO2 fibers were successfully produced. This two-step process seems to easily be extended to synthesizing other hollow oxide fibers with good crystallinity and well-controlled wall thickness.