Rutile TiO(2.) Microspheres with Exposed Nano-Acicular Single Crystals for Dye-Sensitized Solar Cells

Uniquely structured rutile TiO(2) microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 degrees C for 2 h, the rutile TiO(2) microspheres with a high surface area of 132 m(2)/g have been utilized as a light harvesting enhancement material for dye-sensitized solar cells (DSSCs). The resultant DSSCs exhibit an overall light conversion efficiency of 8.41% for TiO(2) photoanodes made of rutile TiO(2) microspheres and anatase TiO(2) nanoparticles (mass ratio of 1:1), significantly higher than that of pure anatase TiO(2) nanoparticle photoanodes of similar thickness (6.74%). Such a significant improvement in performance can be attributed to the enhanced light harvesting capability and synergetic electron transfer effect. This is because the photoanodes made of rutile TiO(2) microsphere possess high refractive index which improves the light utilisation efficiency, suitable microsphere core sizes (450-800 nm) to effectively scatter visible light, high surface area for dye loading, and synergetic electron transfer effects between nanoparticulate anatase and nano-acicular rutile single crystals phases giving high electron collection efficiency