Aligned TiO2 Nanorods and Nanowalls

Well-aligned rutlie and anatase TiO 2 nanorods as well as anatase TiO 2 nanowalls have been synthesized using a template- and catalyst-free metalorganic chemical vapor deposition (MOCVD) method. Structural analyses indicate that single-crystalline rutile and anatase TiO 2 nanorods were formed at 630 °C and 560 °C, respectively, while anatase TiO 2 nanowalls composed of well-aligned nanorods were formed at 535 °C. Optical characterizations of these TiO 2 nanostructures show that the band gap energies for indirect transistion of the rutile TiO 2 nanorods and anatase TiO 2 nanorods as well as nanowalls are at 3.0 and 3.2 eV, respectively.