Fabrication and capacitance of Ni2+–Fe3+ LDHs/MnO2 layered nanocomposite via an exfoliation/reassembling process

Ni2+–Fe3+ layered double hydroxides (LDHs)/MnO2 layered nanocomposite has been fabricated by using both layer-by-layer self-assembly method and flocculated technology, based on electrostatic interaction of positively charged Ni2+–Fe3+ LDHs nanosheets and negatively charged MnO2 nanosheets. Ultraviolet–visible spectroscopy is used to probe the dynamic growth of the multilayer film, exhibiting progressive enhancement of optical absorption due to the assembly of Ni2+–Fe3+ LDHs nanosheets and MnO2 nanosheets. The assembled Ni2+–Fe3+ LDHs/MnO2 nanocomposite has been characterized by XRD, SEM and TEM. The electrochemical property of the synthesized Ni2+–Fe3+ LDHs/MnO2 layered nanocomposite has been studied using cyclic voltammetry in a mild aqueous electrolyte. The Ni2+–Fe3+ LDHs/MnO2 nanocomposite exhibits a relative good capacitive behavior in a neutral electrolyte system, and its initial capacitance value is 104 F g−1.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ni2+–Fe3+ LDHs/MnO2 layered nanocomposite has been fabricated via both layer-by-layer self-assembly and flocculated methods. ► Ni2+–Fe3+ LDHs nanosheets and MnO2 nanosheets can be deposited onto multilayer film uniformly by electrostatic interaction. ► Ni2+–Fe3+ LDHs/MnO2 layered nanocomposite exhibits a relative good capacitive behavior.