Synthesis, Luminescence and Thermal Properties of PVA–ZnO–Al 2 O 3 Composite Films: Towards Fabrication of Sunlight-Induced Catalyst for Organic Dye Removal

Poly(vinyl alcohol) (PVA)–ZnO–Al2O3 composite films have been prepared by the addition of different compositions of ZnO and Al2O3 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 Al2O3 onto PVA and interactions among ZnO, Al2O3 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–Al2O3 composite films could be greatly improved by the incorporation of ZnO and Al2O3 into the system. The glass transition temperature (Tg) were increased for the composite samples using ZnO and Al2O3. Differential scanning calorimetry (DSC) measurements revealed that the melting temperature (Tm) of PVA–ZnO–Al2O3 composite films are significantly higher (~ 12 to 25 °C) than PVA. The photocatalytic measurements exhibited better photocatalytic degradation ability of PVA–ZnO–Al2O3 composites over PVA. Such photocatalytic capacity makes the PVA–ZnO–Al2O3 composite films promising candidates for the removal of organic dyes for water purification.