Pristine and hybrid nickel nanowires: template-, magnetic field-, and surfactant-free wet chemical synthesis and Raman studies

Abstract

Nickel nanowires of high purity and various aspect ratios were synthesized by a wet chemical reduction method without the assistance of surfactants, templates, and external magnetic field. The observed unique optical absorption features of nickel nanowires are highly dependent on the nanowire dimensions. In order to tailor the physical and chemical properties of the nanowires, we have incorporated functionalities in the form of tellurium and zinc oxide coating on them by overgrowth processes using simple wet chemical reactions. The pristine and functional nanowires were characterized by different microscopic and spectroscopic techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal Raman microscopy, X-ray diffraction spectroscopy (XRD), and UV-visible spectroscopy. Our system provides additional details into the growth of anisotropic Ni nanowires, especially in the absence of surfactants, templates, and external magnetic field. We have also demonstrated surface-enhanced Raman scattering (SERS) activity of the Ni nanowires using crystal violet as the probe molecule.