G. S. Anjusree, A. M. Asha, K. R. V. Subramanian, N. Sivakumar, A. Sreekumaran Nair, Shantikumar V. Nair, Avinash Balakrishnan
August 16, 2013
In the present study, ultrafine TiO 2 nanowires (∼80 nm in diameter) exhibiting large aspect ratio in the order of 10 3 were synthesized hydrothermally. Phase and morphological analysis of the nanowires was carried out using X-ray diffractometry, X-ray photoelectron spectroscopy and scanning electron microscopy. High resolution transmission electron microscopy revealed the wire exhibiting growth in (101). A Tauc plot derived from UV analysis showed the average band gap values for nanowires to be less than for nanoparticles of similar diameter. It was observed that nanowires exhibited a high degree of photoactivity in an eosin-based dye system which was found to be 20 – 30 % more than that of nanoparticles. This high photoactivity in nanowires was attributed to the longer charge retention which was observed during lifetime measurements, resulting in easy radical formation and dye degradation. Lifetime measurements on the nanowires showed the recombination time to be 54 ns as compared to 43 ns for nanoparticles.