Exploring the growth kinetics of novel and diverse morphologies in nickel oxide nanostructures

Abstract

This study focuses on the synthesis and characterization of nickel oxide (NiO) nanostructures with diverse morphologies, including nanoflowers, nanocapsules, and nanosnakes, achieved through a cost-effective hydrothermal method. Structural analysis using X-ray diffraction (XRD) confirmed the face-centered cubic crystal (FCC) structure of the NiO nanostructures, with accurate fitting of diffraction peaks achieved through Rietveld refinement within the Fm-3 m space group. The Ni-O bond lengths were determined as 2.0789 Å for nanocapsules, 2.1039 Å for nanoflowers, and 2.0824 Å for nanosnakes based on the 1D profile. The calculated average crystallite size, microstrain, and crystallite size using the Scherrer formula ranged from approximately 6 nm to 20 nm. The study investigates the formation mechanisms underlying the observed diverse morphologies of NiO nanostructures, which were further confirmed by field emission scanning electron microscopy (FESEM). Additionally, the electrochemical properties of the synthesized NiO nanostructures were evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Notably, the nanoflowers demonstrated a higher specific capacitance compared to the nanocapsules and nanosnakes. This comprehensive investigation provides valuable insights into the growth kinetics, structural properties, and electrochemical behavior of novel NiO nanostructures, offering potential applications in energy storage.