A Simple and Facile Electrochemical Route to Synthesis of Metal Hydroxides and Oxides Ultrafine Nanoparticles (M=La, Gd, Ni and Co)

Ultrafine M(OH)n (M=La, Gd, Ni and Co) nanoparticles were electrochemically deposited from an additive–free M(NO3)n (0.005 M) low-temperature bath on a steel substrate at the constant current density of 1 mA cm−2. Heat–treatment of the prepared M(OH)n nanoparticles at 700oC led to formation of the oxide nanoparticles. The morphologies, crystal structures and compositions of the prepared products were determined by means of scanning (SEM) and transmission (TEM) electron microscopy as well as X-ray diffraction (XRD) and FT-IR spectroscopy. The results showed that the prepared M(OH)n samples are composed of ultrafine particles with the size of about 5 nm. After heat–treatment, the obtained products were well–crystallized phases of oxide nanoparticles with a size of around 10 nm. It was concluded that low-temperature cathodic electrodeposition offers a facile and feasible way for the preparation of ultrafine particles of metal oxides and hydroxides.