Synthesis of nickel nanowires by reduction of nickel formate in polyol medium

Linear nanostructures with different length to diameter ratios were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium. The effect of the synthesis conditions such as temperature, reduction time, and nickel formate concentration on the reduction products was studied. Morphology and properties of the nickel nanoparticles were studied by X-ray diffraction, scanning and transmission electron microscopy. It was shown that at 130 °C, well-crystallized metallic nickel in the form of nanowires of about 100 nm in diameter and of 2-4 microns in length is formed in the system. An increase in the reaction temperature up to 150 °C results in an increase in the reduction rate, a decrease in the particles size to 50 nm and changes the morphology of the particles. It was shown that an increase in the concentration of nickel formate in the initial solution does not affect the particles size but leads to an increase in their aggregation. An increase in the synthesis time leads to a substantial increase in the length of the nanowires, while their diameter increases slightly.