| 초록 |
Metal nanoparticles with different sizes exhibit different catalytic properties in terms of activity, selectivity and stability due to their controlled surface-to-volume ratios, facet and electronic structures. For the synthesis of gold nanoparticles with specific sizes, various organic chemicals are mainly used not only as solvents but also as surface-stabilizing agents. However, since organic solvents are toxic substances that pollute the environment, many scientists are making efforts to develop eco-friendly synthesis routes for metal nanoparticles using water as a green solvent. In this study, we synthesized gold nanoparticles with controllable sizes using water as a solvent. Both tannic acid and sodium citrate are used as two competing reducing agents. Tannic acid, a stronger reducing agent, promotes nucleation of the gold precursor while sodium citrate, a weaker reducing agent, promotes the growth of the gold nuclei and plays a role as a stabilizer. Synthesis variables with tannic acid to gold precursor ratio and temperature were investigated. The citrate-stabilized gold nanoparticles formed a spherical shape with a size below 10 nm, which were characterized by TEM. |
