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

• Published in: Inorganic chemistry communications Vol. 158; p. 111455
• Main Authors: Virgin Jeba, S., Sonia, S., Sivaganesh, D., Dhanpal Jayram, Naidu, Jinitha, C.G., Ramachandran, R., Annlin Bezy, N., Satheesh Kumar, T., Lesly Fathima, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2023
• Subjects: Electrochemical characterization; Electron density distribution; Energy storage applications; Growth kinetics; Nickel oxide nanostructures; Rietveld refinement; Electrochemical characterization; Rietveld refinement; Nickel oxide nanostructures; Energy storage applications; Growth kinetics; Electron density distribution
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2023.111455

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•The hydrothermal synthesis method was employed to fabricate NiO nanostructures including nanoflowers, nanocapsules, and nanosnakes.•A unique morphology, referred to as “nanosnakes,” was successfully synthesized and reported for the first time in this study.•The growth mechanism of the synthesized nanoflowers, nanocapsules, and nanosnakes was elucidated, highlighting the involvement of crystallization, Ostwald ripening, and self-assembly processes.•Rietveld refinement analysis was employed to determine the structural parameters of NiO nanostructures, providing precise information about their crystal structure, lattice parameters, and phase purity.•The chemical bonding nature of NiO nanoflowers, nanocapsules, and nanosnakes was analyzed, and the 3D unit cells of these structures were displayed, providing valuable insights into their crystal structure and arrangement.
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.