TiO_2 nanorods integrated with titania nanoparticles: Large specific surface area 1D nanostructures for improved efficiency of dye-sensitized solar cells (DSSCs)

摘要

In this work, the impact of alkali concentration on the formation of novel one dimensional TiO2 nanostructures has been studied. The variation of alkali concentration resulted in the change of morphology and structure of P25 nanoparticle precursors under hydrothermal conditions, as confirmed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption, X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The effects of the annealing temperatures on the surface oxygen vacancies were also studied under various temperatures. In higher NaOH concentrations under annealing, these nanostructures have a peculiar appearance consisting in nanorods with nanoparticles grown on their surface and hence designated herein as "integrated TiO2 nanorods". The prepared nanostructures were employed as main precursors of photoanode and their performance was fully investigated in dye-sensitized solar cells (DSSCs). TiO2 nanostructures prepared from 12 M alkaline solution at 300 degrees C had the largest specific surface area (363.15 m(2)/g) and the best efficiency improvement was about 41% for these TiO2 nanostructures compared to the P25 nanoparticles.