Novel fabrication of modulated carpenterworm-like zinc oxide/polyacrylonitrile composite nanofibers for photocatalytic degradation of methylene blue dye

Abstract

Abstract Novel zinc oxide/polyacrylonitrile (ZnO/PAN) composite nanofibers with modulated carpenterworm-like and other ZnO morphologies were fabricated by simple thermal ultrasonication expansion method. The effect of different ultrasonication temperatures and immersion solutions on morphologies, microstructure and properties of the composite nanofibers were investigated by using field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and ultraviolet-visible spectroscopy. A possible mechanism for various morphologies of ZnO/PAN composite nanofibers at different reaction conditions was presented, and carpenterworm-like hierarchical structure with many smaller ZnO nanorods (diameter of about 201 nm) uniformly anchored onto the PAN nanofiber surface for 80-ZA composite nanofibers at thermal ultrasonication temperature of 80 °C and immersing in zinc ammonia solution. Compared to 60-W immersed in water at thermal ultrasonication temperature of 60 °C, the composite nanofibers fabricated in zinc ammonia solution (especially for 80-ZA) showed improved thermal stability and higher photocatalytic activity for methylene blue (MB). Compared to 60-W, decomposition temperature at 5% weight loss (T5%) was increased by 23 °C from 292 to 315 °C for 80-ZA. Meanwhile, 80-ZA showed higher photocatalytic degradation ratio of about 99.2% than 90.9–96.4% for 60-W and other samples after simulated sunlight irradiation for 7.5 h.