Temperature and solution assisted synthesis of anisotropic ZnO nanostructures by pulsed laser ablation

Abstract Laser ablation of Zn target in water, ammonium nitrate and cetyltrimethyl ammonium bromide (CTAB) was carried out to synthesize spherical, nanoflakes, nanosquares, nanoflowers and branched nanorods ZnO structures. Morphology of the ZnO nanostructures is controlled by varying ambient condition around laser generated plasma by means of either liquid temperature or addition of surfactant CTAB. In situ heating at temperature to 45, 65 and 85 C resulted in morphology variation from spherical to nanoflakes while ex situ heating at 65 C resulted in aggregation of spherical nanoparticles into nanosquares. Finally, simultaneous variation of CTAB and temperature (in situ and ex situ) generated nanoflakes, nanoflowers, nanosquares and branched nanorods. Highly anisotropic nano-flakes, nano-flowers, nano-squares and branched-nanorods structures display distinct optical absorption and emission behavior.