A rapid hydrothermal route to sisal-like 3D ZnO nanostructures via the assembly of CTA+ and Zn(OH)2-4:: growth mechanism and photoluminescence properties

A 3D ZnO nanostructure with sisal-like morphology has been synthesized in the temperature range 120-220 degrees C by a rapid hydrothermal route (30 min) via the assembly of CTA(+) and Zn(OH)(4)(2-). The obtained samples are hexagonal wurtzite structures and they exhibit special optical properties with a red-shift of about 20 nm compared to the corresponding nanorods and nanowires. The sisal, constructed of many nanorods, possesses typical tapering features with tip size 80-100 nm. The effects of CTAB, NaOH, reaction time and temperature were investigated. Results show that the concentration of CTAB and Zn2+/OH- molar ratio play important roles in the fabrication of uniform and pure ZnO samples. On the basis of structural information provided by XRD, SEM, TEM, and HRTEM, a growth mechanism is proposed for the formation of sisal-like 3D ZnO nanostructures.