Synthesis of hierarchical Ni11(HPO3)8(OH)6 superstructures based on nanorods through a soft hydrothermal route

In this paper, we reported the successful synthesis of hierarchical Ni11(HPO3)8(OH)6 superstructures based on nanorods via a facile hydrothermal route, employing NiCl2·6H2O and NaH2PO2·H2O as the reactants in the presences of polyvinylpyrrolidone (PVP) and CH3COONa·3H2O. The reaction was carried out at 170 °C for 10 h. HPO32− ions were provided via the dismutation reaction of H2PO2− ions in a weak basic solution. The as-obtained products were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometry (EDS), field emission scanning electron microscopy (SEM), selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM). Some factors influencing the morphology of the hierarchical Ni11(HPO3)8(OH)6 nanorods, such as the reaction temperature, time, the amounts of PVP and CH3COONa, and the initial concentration of Ni2+ ions, were systematically investigated. A possible growth mechanism was proposed based on experimental results.