One‐step hydrothermal synthesis of ZnO microtubes with an efficient photocatalytic activity

Abstract In this work, the novel rod‐like ZnO microtubes were successfully synthesized via one‐step simple, non‐toxic, fast and economical hydrothermal route. The as‐obtained microtubes were characterized in detail with X‐ray diffraction, scanning electron microscope, UV–visible diffuse reflectance spectroscopy, Fourier‐transform infrared spectroscopy, steady‐state photoluminescence spectrum and surface photovoltage spectroscopy. The photocatalytic activity of the as‐obtained microtubes was evaluated by degradation of methylene blue. The results indicated that the ZnO microtubes, exhibited higher photodegradation efficiency of 95% under UV light irradiation ( λ ≤ 420 nm) for 20 min. The photodegradation could be described as the pseudo‐first‐order kinetics with apparent rate constant of 0.126 min ‐1 , which was based on the unique morphology of ZnO. Moreover, ZnO microtubes maintained a good photostability after three consecutive cycles. Unique microtubes can be applied practically for dye waste‐water treatment.