Shape-controlled agglomeration of TiO2 nanoparticles. New insights on polycrystallinity vs. single crystals in photocatalysis.

The photocatalytic activity of TiO 2 photocatalysts depends mainly on its crystal phase composition, primary particle size and specific surface area. Shape manipulation is an interesting way to increase the photocatalytic efficiency. The shape-tuning can be carried out at different levels, both at single crystal and polycrystalline agglomeration levels. The aim of our present study was to compare the structural and photocatalytic performances of two type/level of crystal organization of TiO 2 , namely single crystal shaping vs. polycrystalline/shape tailored agglomeration. The morphological analysis was achieved by XRD, SEM, TEM, Raman spectroscopy, DRS. The photocatalytic performance of the materials was evaluated by the degradation of a model pollutant (phenol). It was found, that both shape manipulating approaches bear the necessary potential which can be exploited in future development of efficient photocatalysts’ synthesis procedures. [ABSTRACT FROM AUTHOR]