α-Fe2O3/ZnO nanocomposite as an efficient photocatalyst for wastewater treatment and flexible electronic device applications

Abstract

In this work, we report the synthesis of pure α-Fe2O3, ZnO, and α-Fe2O3/ZnO nanomaterials by a simple sol-gel method for photocatalytic dye degradation and flexible electronic applications. XRD results reveal that the synthesized samples were rhombohedral and hexagonal wurtzite structures of α-Fe2O3, and ZnO nanoparticles respectively. α-Fe2O3/ZnO composites exhibit the mixed peaks of both α-Fe2O3 and ZnO crystal structures which substantiate the formation of α-Fe2O3/ZnO composites. From the optical studies, the band gaps of α-Fe2O3, ZnO, α-Fe2O3/ZnO composites of (1:1), and (1:2) ratios are calculated as 2.11, 3.14, 2.87, and 2.92 eV respectively. Compared to pure α-Fe2O3 and ZnO nanoparticles, α-Fe2O3/ZnO composites of (1:2) ratio exhibit superior photocatalytic behaviour under the irradiation of the natural sunlight and also show good stability for up to five cycles. From the scavenger studies, it is concluded that hydroxyl radicals are the major contributors to the photocatalytic decolourization of methylene blue dye molecules. The dielectric behaviour of the pure and blended nanoparticles is also investigated in a wide range of frequencies using impedance spectroscopy. The nanoparticles embedded in Polyvinyl Alcohol (PVA) or α-Fe2O3/ZnO/PVA thin films demonstrate a higher dielectric constant (32.68) and lower loss factor (3.32) than pristine PVA. The AC conductivity (σ AC) of α-Fe2O3/ZnO composites of (1:2) ratio is 10− 12 S/cm. These findings indicate the possibilities of using α-Fe2O3/ZnO/PVA composites as a flexible dielectric material for the fabrication of flexible electronic devices.