Effect of tannic acid concentrations on the particle size of copper nanoparticles

Copper-tannic acid (Cu-TA) nanoparticles can be synthesized through green synthesis by reacting copper (II) nitrate solution with tannic acid as a natural reducing agent without using hazardous materials. Tannic acid is designed as a reducing agent for Cu2+ and a stabilizing agent for nanoparticles. Tannic acid contains hydroxyl and carbonyl groups that act as ligands that bind to metal ions to form complex compounds. In this study, the formation of copper-tannic acid nanoparticles was represented by mixing copper (II) nitrate with various volumes of tannic acid (10 mL, 20 mL, 30 mL, and 90 mL). Copper-tannic acid nanoparticles were successfully characterized by the color change of the copper ion solution from blue to a light brownish yellow. The synthesized copper-tannic acid nanoparticles were characterized by UV-Vis absorption spectra using a UV-Vis spectrophotometer. The nanoparticles' size was characterized by a particle size analyzer. It shows that the smallest amounts of copper-tannic acid were synthesized at 10 mL of Cu(NO3)2 solution and 90 mL of tannic acid solution.