Hollow ZnO Nanofibers for Efficient Photocatalytic Degradation of Methylene Blue

In this work, hollow-structured nanofibers with densely and uniformly distributed ZnO nanorods were successfully prepared by a combination of coaxial electrospinning, heat treatment, and hydrothermal synthesis, exhibiting excellent photocatalytic degradation performance. The morphological and structural characteristics of hollow ZnO nanofibers obtained at different heat treatment temperatures were systematically investigated, and their photocatalytic degradation performances were compared through degrading methylene blue (MB) under ultraviolet (UV) irradiation. It was found that the hollow ZnO nanofibers obtained by heat treatment at 280 °C exhibited the best photocatalytic degradation performance due to their optimal morphology and structure. Their photocatalytic degradation efficiencies for MB under 3 h of UV light and natural sunlight were 94.70% and 92.95%, respectively. Furthermore, cyclic stability tests were conducted on the optimal sample, revealing that its degradation efficiency remained at 89.96% after three cycles, demonstrating its excellent reusability.