Fast and one-step synthesis of small ZnO nano-tetrapods Using CO2 laser in ambient air: physical properties

Abstract

In this study, a simple laser ablation method was developed to synthesize small nano-tetrapods as a fast and one-step process. The used laser was a CO2 laser with 10.6 μm of wavelength with proper thermal penetration depth for performing the ZnO tetrapods in the interaction with Zn target in ambient air. The samples were produced in two different morphologies: nanorods and nano-tetrapods, in two states. The optical, structural, and morphological properties were studied by performing room-temperature scanning electron microscopy (FESEM), dynamic light scattering (DLS), x-ray diffraction (XRD), photoluminescence (PL), and UV-visible analysis. The FESEM analysis shows that the diameters of the produced ZnO nano-tetrapods are approximately 10–13 nm by arm length of about 250 nm with excellent morphologies. The XRD results indicated that the nanoparticles are in phase with pure ZnO and both morphologies have the Hexagonal wurtzite. Two high peaks in the PL spectrum were observed on UV and visible spectrums, a peak in the red wavelength was demonstrated that has been rarely found for ZnO nanostructures and show the capability of produced particle to use in lightning industry. UV–vis spectral of dispersed particles in deionized water determined that nanorods and nano-tetrapods have peaks at 374 nm and 370 nm, respectively. The spectrums showed produced nanostructures have a broad absorption band from ultra-violet to visible regions, leading the decreases the absorption when the wavelength increases slowly to the visible spectrum, that show capability to apply in photocatalytic processes. Therefore, results show the capability of the introduced method to access two different morphologies of ZnO and significantly the nano-tetrapods structure with well physical and morphological properties.