Influence of ball milling on textural and morphological properties of TiO2 and TiO2/SiO2 xerogel powders applied in photoanodes for solar cells

Abstract

In this work, nanocrystalline and mesoporous titania and titania/silica materials were developed, using the sol–gel method, to be applied as alternative material in solar cell devices. The materials present the silica well dispersed in the titania network, allowing efficient anchoring of the sensitizer on the TiO2 surface and enabling fast electron injection that is currently observed between ruthenium complexes and TiO2. The materials were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy and ultraviolet-visible spectroscopy. The ball milling processing, mainly at 500 rpm, showed to be effective in obtaining adequate textural and morphological properties of the particles, which allow getting a good packing of the photoanode. The use of sol–gel method associated to ball milling results in materials with enhanced electrical properties and high dye loading, which increase the efficiency of the solar devices being that the best device presented the solar cell efficiency 5.5 %.