Electrospun ZnO nanofibers thin films for the methylene blue degradation driven by natural sunlight

Abstract

• Two-step synthesis of homogeneous ZnO nanofibers thin films on glass substrates. • Immobilization of recyclable nanostructured ZnO photocatalyst for MB degradation. • High MB photodegradation percentage in 3 consecutive experiments driven by sunlight. In this work, we report the synthesis of polyvinyl alcohol-Zn acetate fibers on glass substrates by electrospinning technique, which after calcination become ZnO crystalline nanofibers thin films. The thin films are homogeneous with the intrinsic porosity of the fiber morphology and well-adhered to the substrate. We analyzed the properties of the ZnO nanofibers thin films by SEM, XRD, and TGA. Besides, the ZnO nanofibers thin films were applied to the photodegradation of methylene blue (MB) in aqueous solutions under sunlight. The MB photodegradation in the solutions was evaluated by UV–vis absorption at different exposure times to sunlight. The results revealed that the nanofibers thin films produce 96.4% degradation percentage of the MB solutions. Furthermore, after the photodegradation experiments, the photocatalytic thin films remain integral and well adhered to the substrate, then they can be reutilized in subsequent photodegradation experiments. The ZnO nanofibers thin films can achieve a high degradation percentage of the MB solutions in at least three consecutive photodegradation experiments.