Investigation of the effect of synthesis parameters including reaction temperature and initial concentration of Cu precursor on the size and size distribution of zero-valent Cu nanoparticles by UV–Vis spectroscopic analysis

One of the important features of Cu nanoparticles is their localized surface plasmon resonance peaks in the visible light region that are used for their optical characterization [1]. The synthesis temperature of nanoparticles and initial concentration of precursor are the most important parameters that affect the size and size distribution of metal nanoparticles. At the optimum temperature and initial concentration of precursor, the purity of the product is increased and oxidation of nanoparticles is reduced [2]. In this study, Copper nanoparticles were synthesized by a convenient and rapid chemical reduction method in ambient condition using Cu(NO3)2.3H2O as a precursor, hydrazine hydrate as reducing agent and deionized water as solvent. For the investigation and optimization of the effect of initial concentration of Cu precursor and reaction temperature on the size and size distribution of Cu nanoparticles, several experiments were performed. All parameters were fixed during the experiments except the initial concentration of Cu(NO3)2.3H2O and reaction temperature. The UV–Vis spectra of prepared Cu nanoparticles were used to investigate the effect of initial concentration of Cu precursor and reaction temperature on the size and size distribution of obtained Cu nanoparticles. According to the results, smallest copper nanoparticles with a narrow size distribution were obtained in the optimum concentrations of Cu(NO3)2.3H2O as 41 mmol l−1 and the optimum reaction temperature was determined to be 120 °C.