Vertically aligned single-crystal zinc sulfide nanotubes with hexagonal cross-sections and optical properties

• Vertically aligned single-crystal ZnS nanotubes with hexagonal cross-section.
• The process of preparation is simple and environmentally friendly.
• Excellent optical property superior to ZnS NWs reported previously.
• ZnS is of high-yield and inexpensive.

Without the presence of any catalysts or templates, single-crystal zinc sulfide (ZnS) nanotubes have been successfully synthesized in bulk quantity by a facile and controllable process based on thermal evaporation of ZnS powders. X-ray diffraction (XRD), energy dispersed X-ray spectrometry (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) were used to characterize the products. The results indicate that the synthesized ZnS nanotubes are single-crystalline with hexagonal cross-sections. The diameters of the ZnS nanotubes vary from 200 to 700 nm and lengths are about several micrometers. The growth of ZnS nanotubes is controlled by the conventional rolling mechanism. And the room temperature photoluminescence (PL) indicated a stable and strong green emission centered at about 542 nm, which may result from nanotube effects.