Nickel Oxide/Reduced Graphene Oxide Nanocomposites

Nickel oxide (NiO)/reduced graphene oxide (rGO) nanocomposites are well known for their exceptional characteristics in various applications. Reduced graphene oxide differs from graphene oxide in terms of morphological aspects, quality, functionalized groups, and crystallinity. Several attempts to synthesize NiO/rGO have been documented in studies. This chapter discusses numerous ways to synthesize NiO/rGO, and a literature review reveals that the most commonly used techniques for synthesizing NiO/rGO are the sol-gel technique, hydrothermal and solvothermal methods, and electrodeposition. The chapter also discusses various characterization techniques used to study the morphological, structural, and chemical bonding characteristics, as well as the electrochemical properties of NiO/rGO. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy are generally used to study these properties. Various peaks were observed in the XRD spectra of the NiO-rGO nanocomposite at 37.2°, 43.3°, 62.8°, 75.4°, and 79.3°, corresponding to crystal planes of (111), (200), (220), (311), and (222), respectively. The Raman spectra of rGO generally exhibit the D-band and G-band. After the synthesis of NiO/rGO, shifts in these bands can reveal insights into the level of interaction between NiO and rGO.