Hydrothermal synthesis of the sealed ZnO nanotube and its growth mechanism

In this article, a sealed nanotube of ZnO was successfully obtained by a simple hydrothermal technique, which employed Hexamethylene tetramine (HMT) and Fluorinion (F−) as the active agents. The rod-like nanotubes structures were observed through field-emission scanning electron microscopy. The high-resolution transmission electron microscope exhibited a shell-enclosed nanotube structures. On the basis of experimental observations, including temperature, pH of the solution and acting agents, a growth mechanism was proposed. The as-prepared nanostructures showed excellent gas sensitivities to different gases (ethanol, ammonia gas, formaldehyde gas) with a quite low concentration respectively.