Synthesis of Shape-Tailored WO₃ Micro-/Nanocrystals and the Photocatalytic Activity of WO₃/TiO₂ Composites.

A traditional semiconductor (WO₃) was synthesized from different precursors via hydrothermal crystallization targeting the achievement of three different crystal shapes (nanoplates, nanorods and nanostars). The obtained WO₃ microcrystals were analyzed by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). These methods contributed to the detailed analysis of the crystal morphology and structural features. The synthesized bare WO₃ photocatalysts were totally inactive, while the P25/WO₃ composites were efficient under UV light radiation. Furthermore, the maximum achieved activity was even higher than the bare P25's photocatalytic performance. A correlation was established between the shape of the WO₃ crystallites and the observed photocatalytic activity registered during the degradation of different substrates by using P25/WO₃ composites.