Hydrothermal synthesis of Ni-Co-Cu alloy nanoparticles from low nickel matte

Ni-Co-Cu alloy nanoparticles were synthesized using a hydrothermal method from the low nickel matte. The effects of synthetic parameters such as hydrothermal temperature, pH value of precursor solution, added amount of PVP and reaction time on the chemical compositions, micromorphology and magnetic properties of the prepared products were systematically investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), High-resolution TEM (HRTEM) and Vibrating sample magnetometer (VSM). It is indicated that the size of as-prepared Ni-Co-Cu alloy nanoparticles decreased with the increasing of reaction temperature (150 °C-180 °C), pH value (10.0–12.0) and the added amount of PVP (0–1.0 g mL−1). Under the optimal experimental conditions, pure Ni-based alloy (Ni0.95Co0.03Cu0.02) which exhibited good magnetic properties with the saturation magnetization (Ms) value of 48.72 emu g−1 and the coercivity (Hc) value of 126.39 Oe, respectively, was achieved. Moreover, the main impurity ions, such as Fe ions in the leaching solution of low nickel matte, have no effect on the purity of as-prepared alloy nanoparticles. This paper may provide a new way for the synthesis of alloys from natural minerals for the first time.