Synthesis and growth discussion of one-dimensional MgO nanostructures: Nanowires, nanobelts, and nanotubes in VLS mechanism

Three kinds of one-dimensional (1D) MgO nanostructures: nanowires, nanobelts, and nanotubes were synthesized through introducing the low-melting point mental Sri as catalyst in the chemical vapor deposition route. The morphology and crystalline structure were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The detailed growth processes of these structures were discussed. A conventional VLS mechanism, explicated VLS mechanism, and VLS mechanism combined with second evaporation-oxidation process were proposed to explain the growth of nanowire, nanobelt, and nanotube, respectively. The establishment of growth models on nanobelt and nanotube gave a new annotation of VLS mechanism different with previous reports, and the growth analyses are helpful to comprehensively understand VLS mechanism. These results have important referenced significance in fabrication of various 1D nanostructures. Furthermore, the obtained nanostructures may find various applications as functional building blocks in nanodevices.