The effect of PH on the formation of nickel nanostructures by chemical reduction method

The synthesis of nickel (Ni) nanostructures through chemical reduction method using hydrazine (N2H4.6H2O) as a reducing agent is reported. It was found the ratio of 6.65 of NaOH over NiCl2 is necessary for the formation of pure nickel nanoparticles. NaOH was used to control the pH of solutions. Field Emission Scanning Electron Microscopy (FESEM) revealed that by varying [OH-]/[Ni2+] molar ratio, various types of Ni nanostructures with size between 20 to 800 nm are obtained. Changing the pH from 8.7 to 9.5 resulted in formation of Ni wool- like nanostructure composed from chain-like nanostructure particles. The presence of nickel nanoparticles was confirmed with phase analysis using X-ray diffraction (XRD). Results show that the formation of pure Ni metal nanoparticles of wool-like nanostructure only occur when [OH-]/[Ni2+] molar ratio was tailored to higher than four