Oct 12, 2010
High field anodization induces ultra-thin TiO2 nanotubes
Ultra-thin TiO2 nanotubes with controllable parameters (diameter and length) can be fabricated under high field anodization, leading to high-speed film growth. In addition, an annealing process can be used to obtain a monodisperse and double-pass TiO2 nanotubular layer with a gradient pore diameter and ultrathin tube wall. The approach is simple and cost-effective and the arrays could be used to improve dye-sensitized solar cells (DSSCs).
Researchers at Shanghai Jiao Tong University, China, are studying the fabrication and practical application of nanomaterials. One of the team's major projects is the investigation of ultra-thin TiO2 nanotubes. A higher anodic voltage and longer anodization time are critical factors in the whole two-step anodization, and enable an ideal TiO2 nanotube film with a unique double-pass structure to be obtained.
The chief advantages of this method are the ultra-thin nanotube wall (nearly 10 nm) and high-speed growth rate (0.40–1.00 µm/min–1), meanwhile, the barrier layer detaches automatically.
Art turned into application
The team's results provide a simple and cost-effective approach to fabricating high-quality ordered TiO2 nanotube arrays with ultra-thin walls for a variety of critical practical energy applications involving DSSCs. These TiO2 nanotube arrays will enable developers to load much more dye, reduce the carrier recombination leading to more efficient charge separation and provide a unidirectional electric channel, which is essential for photovoltaics and photocatalysis applications.
More details can be found in the journal Nanotechnology.
About the author
The study was conducted by Dr Yuan Xiaoliang, Prof. Zheng Maojun, Prof. Ma li and Prof. Shen Wenzhong, who are based at the Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education ), Department of Physics, Shanghai Jiao Tong University in Shanghai, People's Republic of China. The group is engaged in research on condensed matter spectroscopy and optoelectronic device physics. Wide wavelength coverage (100 nm – 500 µm), low temperature (1.6K), ultrafast process (femtosecond), high superconducting magnetic field (17 Tesla) and micro-Raman/PL (<1 m, 325.0 & 514.5 nm lasers) are among the main features of the lab.