A self-growing strategy for large-scale crystal assembly tubes.

Assembled tubular materials have attracted widespread attention due to their potential applications in catalysis, bionics, and optic-electronics. Many versatile methods, including template-assistance and self-assembly, have been developed for tubular materials fabrication. Here we demonstrate a self-growing strategy to prepare large-scale crystal assembly tubes. Addition of the template and the need for the sophisticated equipment are avoided with this method. The sidewall of the tubes composes of a layer of polyhedral crystals that are connected together through grain coalescence. We demonstrate that the assembled tubular structure is obtained by the synergetic effect of the passivation layer and the dissolution-recrystallization process. This facile one-step strategy and the formation mechanism will offer guidance for fabrication of new superstructures.