Polyaniline-Modified TiO2, a Highly Effective Photo-catalyst for Solid-Phase Photocatalytic Degradation of PVC

A series of polyaniline-modified TiO2 photo-catalysts (TiO2@PANI) were prepared via an in-situ polymerization of aniline onto TiO2 nanoparticles. The Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric analyses (TGA) confirmed that the polyaniline (PANI) successfully grafted on the TiO2 NPs. The X-ray diffraction (XRD) patterns showed that the crystalline structure of the TiO2 did not change during the preparation of PANI. Photodegradable nanocomposites were prepared by embedding the photocatalysts into the commercial poly(vinyl chloride) (PVC) samples. The nanocomposite films were compared against pure PVC and PVC-TiO2 films for their photodegradation performances. The photocatalytic activity of the TiO2@PANI catalysts improved with an increase in the inorganic/organic molar ratio. With the TiO2 aniline molar ratio of 10, the PVC-TiO2@PANI nanocomposite film lost about 67% of its weight after 720 h irradiation under UV. Meanwhile, the pure PVC and PVC-TiO2 control films lost about 12 and 45% of their initial weights, respectively. Results showed that the rate at which the PVC is photodegraded can be controlled by the amount of the TiO2 NPs as well as the initial TiO2 aniline molar ratio. The SEM micrograms indicated a rougher and more porous surface for the irradiated PVC-TiO2@PANI compared with controls.