Anatase TiO(2) Nanoparticles with Exposed {001} Facets for Efficient Dye-Sensitized Solar Cells

Anatase TiO(2) nanoparticles with exposed {001} facets were synthesized from Ti powder via a sequential hydrothermal reaction process. At the first-step hydrothermal reaction, H-titanate nanowires were obtained in NaOH solution with Ti powder, and at second-step hydrothermal reaction, anatase TiO(2) nanoparticles with exposed {001} facets were formed in NH(4)F solution. If the second-step hydrothermal reaction was carried out in pure water, the H-titanate nanowires were decomposed into random shape anatase-TiO(2) nanostructures, as well as few impurity of H(2)Ti(8)O(17) phase and rutile TiO(2) phase. Then, the as-prepared TiO(2) nanostructures synthesized in NH(4)F solution and pure water were applied to the photoanodes of dye-sensitized solar cells (DSSCs), which exhibited power conversion efficiency (PCE) of 7.06% (V(OC) of 0.756 V, J(SC) of 14.80 mA/cm(2), FF of 0.631) and 3.47% (V(OC) of 0.764 V, J(SC) of 6.86 mA/cm(2), FF of 0.662), respectively. The outstanding performance of DSSCs based on anatase TiO(2) nanoparticles with exposed {001} facets was attributed to the high activity and large special surface area for excellent capacity of dye adsorption.