Co₂P nanostructures constructed by nanorods: Hydrothermal synthesis and applications in the removal of heavy metal ions

In this paper, we report the successful synthesis of cobalt phosphide (Co₂P) nanostructures built up of nanorods via a simple hydrothermal route using white phosphorus (WP), sodium hypophosphite and cobalt dichloride as starting reactants in the presence of polyvinylpyrrolidone (PVP, 30 K). The as-obtained product was characterized by means of X-ray powder diffraction (XRD), energy dispersive spectrometry (EDS), (high resolution) transmission electron microscopy (TEM/HRTEM), selected area electron diffraction (SAED) and field emission scanning electron microscopy (FESEM). It was found that sodium hypophosphite played an important role in the formation of the Co₂P nanostructures. Some factors influencing the morphology of the product, including the reaction temperature, amount of sodium hypophosphite, surfactant, and so on, were investigated. The capacity of the product to remove heavy metal ions was also studied.