Synthesis of Ni–Cu Solid Solutions by Precipitation in the Supercritical CO 2 Medium

The effect of precipitation conditions of acetate precursors in the supercritical СО 2 medium (temperature, pressure, solvent composition) for the synthesis of mixed Ni–Cu systems is studied. Synthesized samples are characterized by various physicochemical techniques: SEM, nitrogen adsorption, IR-Fourier spectroscopy, and powder X-ray diffraction (XRD). It is shown that the use of water as a cosolvent as well as the performance of the process under supercritical conditions enable the preparation of mixed Ni–Cu systems with the structure of a homogeneous solid solution at the metal atomic ratio Ni/Cu = 1/1.