Topochemical synthesis of Ni2+–Fe3+ layered double hydroxides with large size

Ni2+–Fe3+ layered double hydroxide material with large size up to 4 μm and regular morphology was prepared via a topochemical approach by using urea as a hydrolysis agent and mannitol as a stabilizer. α-type Ni2+–Fe2+ hydroxide with micrometer size and hexagonal shape was firstly prepared, and the effect of the reaction time, total metal ion concentration and the concentration of urea on the particle size and morphology of the α-type Ni2+–Fe2+ hydroxide was investigated. α-type Ni2+–Fe2+ hydroxide material was then oxidized by iodine in chloroform, and hydrotalcite-like Ni2+–Fe3+ LDH material with large size and regular hexagonal morphology was obtained. The obtained Ni2+–Fe3+ LDH material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and FT-IR spectrum (IR), respectively.