Photoanode based on chain-shaped anatase TiO2 nanorods for high-efficiency dye-sensitized solar cells.

Anatase TiO(2) nanorods with large specific surface areas and high crystallinity have been synthesized by surfactant-free hydrothermal treatment of water-soluble peroxotitanium acid (PTA). X-ray diffraction and TEM analysis showed that all TiO(2) nanorods derived from PTA in different hydrothermal processes were in the anatase phase, and high aspect ratio TiO(2) nanorods with chain-shaped structures were formed at 150 °C for 24 h by oriented growth. The nanorods were fabricated as photoanodes for high-efficiency dye-sensitized solar cells (DSSCs). DSSCs fabricated from the chain-shaped TiO(2) nanorods gave a highest short-circuit current density of 14.8 mA cm(-2) and a maximum energy conversion efficiency of 7.28 %, as a result of the presence of far fewer surface defects and grain boundaries than are present in commercial P25 TiO(2) nanoparticles. Electrochemical impedance spectroscopy also confirmed that DSSCs based on the TiO(2) nanorods have enhanced electron transport properties and a long electron lifetime.