Preparation of anatase TiO2 nanotubes and their dye-sensitized solar cells

TiO2 nanotubes were synthesized from commercial rutile powder by means of the hydrothermal method in alkaline solution at temperature of 150 degrees C for 48 hours. The morphology and structure evolutions were characterized with SEM, TEM and X-ray diffraction. The TiO2 nanotubes mixed with Triton X-100 and acetyl acetone were screen-printed onto the glass substrate coated with a transparent conducting oxide (ITO, or tin-doped indium oxide), then sintered at 450 degrees C for 30 minutes to form porous photoanode of dye-sensitized solar cells. A solar cell with active area of 0.28 cm(2) was assembled with N719-coated nanotube-TiO2 electrode, Pt-coated ITO glass and iodide-based ionic liquid electrolyte. The J-V curve was measured using a standard solar simulator (AM1.5 spectrum, 100 mW/cm(2)) and a photoelectric conversion efficiency of 2.17% was obtained.