Aligned TiO2 nanorods and nanowalls

Well-aligned rutlie and anatase TiO2 nanorods as well as anatase TiO2 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 TiO2 nanorods were formed at 630 degreesC and 560 degreesC, respectively, while anatase TiO2 nanowalls composed of well-aligned nanorods were formed at 535 degreesC. Optical characterizations of these TiO2 nanostructures show that the band gap energies for indirect transistion of the rutile TiO2 nanorods and anatase TiO2 nanorods as well as nanowalls are at 3.0 and 3.2 eV, respectively.