Synthesis of nickel and cobalt oxide nanoparticles by pulsed underwater spark discharges

Electrical discharges in liquids are considered an efficient and ecological technique of nanoparticle synthesis via controlled erosion electrodes. Herein, we use spark between Co–Co, Ni–Ni, Co–Ni, or Ni–Co electrodes immersed distilled water to synthesize Co and/or Ni nanoparticles, as well their oxides. When mixed used (Co–Ni Ni–Co), both nanoparticles produced, the major species is dictated by nature anode pin. The characteristics synthesized under varying conditions pulse width (100 500 ns) voltage amplitude (5 20 kV) analyzed transmission electron microscopy. Within investigated discharge conditions, it not possible produce Co–Ni nanoalloys; however, core–shell observed among nanoparticles. Finally, direct optical bandgaps nanomaterials determined using UV-visible absorption spectroscopy.