Synthesis, Luminescence and Thermal Properties of PVA–ZnO–Al2O3 Composite Films: Towards Fabrication of Sunlight-Induced Catalyst for Organic Dye Removal

Poly(vinyl alcohol) (PVA)–ZnO–Al 2 O 3 composite films have been prepared by the addition of different compositions of ZnO and Al 2 O 3 through solvent casting method. Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis) and photoluminescence spectroscopy (PL) spectra revealed the successful incorporation of ZnO and Al 2 O 3 onto PVA and interactions among ZnO, Al 2 O 3 and PVA molecules. PL data indeed showed the enhanced luminescence property of composite films compared with the PVA. Thermogravimetric analysis (TGA) data showed that thermal stability of PVA–ZnO–Al 2 O 3 composite films could be greatly improved by the incorporation of ZnO and Al 2 O 3 into the system. The glass transition temperature (T g ) were increased for the composite samples using ZnO and Al 2 O 3 . Differential scanning calorimetry (DSC) measurements revealed that the melting temperature (T m ) of PVA–ZnO–Al 2 O 3 composite films are significantly higher (~ 12 to 25 °C) than PVA. The photocatalytic measurements exhibited better photocatalytic degradation ability of PVA–ZnO–Al 2 O 3 composites over PVA. Such photocatalytic capacity makes the PVA–ZnO–Al 2 O 3 composite films promising candidates for the removal of organic dyes for water purification.