Synthesis, structural, photocatalytic, wettability and optical properties of TiO2 films on polymethyl methacrylate substrates

Abstract

TiO2 thin films on polymethyl methacrylate (PMMA) substrates were prepared on Al foils using reactive dc magnetron sputtering followed by transformation to the PMMA substrates via chemical method. The films were prepared at different temperature preparation routes of 100, 150 and 200 °C. XRD revealed the formation amorphous structure for films prepared at 150 °C and mixed anatase/rutile crystalline phases with rutile domination at higher-temperature preparation route of 150 and 200 °C. Amorphous or homogeneous and uniform nanoparticles morphologies with particle sizes depended on the temperature preparation route were obtained for the TiO2 films. The optical properties are affected strongly by the temperature preparation route. The optical band gap values increased from 3.05 eV to 3.47 eV with increasing the temperature preparation route from 100 °C to then to 200 °C, respectively. The higher refractive index and the lower extinction coefficient were obtained for the films prepared at 200 °C. The methylene blue underwent effective photodegradation and the hydrophilicity initiated upon UV illumination. The TiO2 film prepared at 200 °C has the highest decomposition efficiency for methylene blue and the lowest water contact angle.