The Role of Hydroxide Ions in the Synthesis of Ni Nanoparticles Using High Temperature Polyol Method

Abstract

This study investigate the role of hydroxide ions (OH-) in the synthesis of Ni nanoparticles through polyol method at the temperature of 180°C. Ni nanoparticles were prepared using ethylene glycol (EG) as the solvent and hydrazine (N2H4) as the reducing agent. Sodium hydroxide (NaOH) was used to introduce the OH-in solutions. Amount of OH-has been controlled through manipulation of OH-/Ni2+ratios. The role of OH-has been discussed in terms of size, morphology and reaction rate. Particles size and morphology were determined by Transmission Electron Microscopy (TEM). X-Ray Diffractometer (XRD) was used to verify the chemical composition of as-synthesized particles. The results demonstrated that at temperature of 180°C, Ni nanoparticles can be synthesized even without the existance of OH-. Although there no significant particles size changes,synthesis without OH-showed the most rapid reaction as compared to samples with OH-. Probable mechanisms for formation of Ni nanoparticles with and without OH-are also discussed. This finding contribute to a new rapid and facile synthesis of Ni nanoparticles.