Influence of Microwave-Hydrothermal Temperature on Synthesis of TiO2 Thin Films on PMMA Substrates from Colloidal Anatase Aqueous Solutions

Nanocrystalline TiO2 films were deposited on polymethylmethacrylate (PMMA) substrates by dip–coating process from colloidal anatase aqueous solutions. Microwave–hydrothermal process treating TiO2 colloidal solutions was applied to enhance crystallization under a mild condition and avoid post–treatment. The as–prepared TiO2 films were characterized and analysed by X–ray diffraction (XRD), UV–visible spectroscopy and atomic force microscopy (AFM). The photocatalytic degradation of Rhodamine B (RhB) under ultraviolet radiation was explored. Results show that pure anatase TiO2 is achieved rapidly using microwave hydrothermal process. The TiO2 suspension becomes uniformly disperse, stable and deposit-free after ultrasonic dispersion. The thin films deposited on unmodified PMMA substrates from the dispersive TiO2 colloidal solution are dense, homogeneous, crack–free, without visible agglomerates and show high photocatalytic activity without post-treatment. Rhodamine B has been degraded over 99 % after 180 minutes under UV irradiation.