Construction Of Nano - Ordered Ordered Multi - Stage Structure Of Cobalt - Nickel Oxide And Its Electrochemical Performance

Constructing electrochemically active but insulating materials (e.g. metal oxides and hydroxides) in oriented nanoarrays has shown their advantages in the field of energy storage and electrochemical catalyst, especially for supercapacitors and HER (hydrogen evolution reaction). Specially, such a nanoarray architecture can offer a large specific surface area and facilitate ion diffusion and electron transportation, resulting in high specific capacitances and remarkable capabilities or the ultrahigh catalyst active. Moreover, the direct growth of active materials on conductive substrates can ensure good mechanical adhesion, which makes the morphology and structure more stable when surface redox reactions occur on the electrode. As an evolution of nanoarrays, hierarchical nanoarrays have been demonstrated to be superior to the single components because of their higher contact area with the electrolyte, higher porosity and increased number of active materials in a unit area, leading to a higher areal capacitance while keeping other criteria better or comparable, as confirmed by our and other groups’work.1. Nio.25Coo.75(OH)2hierarchical nanowire@nanoplatelet arrays were prepared by an in situ conversion from Ni0.5Co1.5(OH)2CO3nanowire arrays in a highly concentrated basic solution at room temperature. These unique hierarchical nanoarrays showed a7times larger areal capacitance and better rate capability than the precursive one dimensional nanowire arrays2. Several hybrid nanoarrays (e.g. Au/Co2(OH)2CO3nanowire arrays, Au/CO3O4nanowires array, AU/CO3O4nanobelts arrays, CO3O4/Au film) were constructed, and they are tested by electrochemical surface-enhanced Raman spectroscopy, we confirmed that the CoO (OH) would be in the redox reaction of cobalt compounds, at the same time there are four valence cobalt generated under the high voltage.3. Nickel nanoparticle array was been fabrication by a combination of a hydrothermal reaction and a solvent thermal reaction, and we confirmed that the nanoarrays materials have a better performance than planar material. NiMoO4nanorod arrays were prepared by a hydrothermal reaction, and the electrochemistry performance were confirmed by tests. And NiMoO4nanorod arrays showed a high capacitance.