Hydrothermal Preparation of Anatase TiO₂ Nanoparticles for Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSSCs) have recently attracted intensive interest because of their simple construction, low cost, and high efficiency of sunlight to electricity conversion. Usually, a mesoporous titanium oxide (TiO₂) film deposited on a transparent electrode is used as a photoanode on which the ruthenium complex dye molecules adsorb. The aim of this work is to prepare pure anatase phase TiO₂ nanoparticles with high surface area for DSSCs application. We used the titanium (IV) n-butoxide as the precursor and acetic acid as a peptizer, after the hydrothermal treatment at 200°C, the anatase TiO₂ (a-TiO₂) can be obtained. The effect of hydrothermal duration on the properties of a-TiO₂ was studied. The TiO₂ products were characterized by XRD, TEM, and BET. The a-TiO₂ particles showed two distinct particle features: the irregular polyhedron and the elongated shaped as observed by TEM. Increasing the hydrothermal reaction time increased the average particle size for both cases and the surface area decreased as well. The a-TiO₂-based DSSCs were prepared with different thickness for the photovoltaic characteristics study. The best efficiency of ~6.61% was obtained for thickness of 24 μm (V_oc = 0.77 V, J_sc = 16.48 mA/cm², FF = 0.56).