Silver nanoparticles were eco-friendly synthesized at room temperature via a Tollens process modified with the stepwise method using eco-friendly precursors (citric acid and acetic acid). The field emission scanning electron spectroscopy was used to study the morphology of silver nanoparticles. The mean size of silver nanoparticles and the components of products were theoretically determined using UV-Vis and X-ray Diffraction spectra. The mole ratio between the silver ion, citric acid and the buffer acid solution (acetic acid) strongly influences the mean size and the composition of the product. The appearance of acetic acid in the buffer acid solution helped increase the efficiency of silver nanoparticles preparation. With the mole ratio n[Ag+]:ncitric:nacetic = 1.0:2.5:2.5, the highest preparation efficiency was obtained, the silver nanoparticles had an average dimension of ˜11 nm and narrow size distribution. The silver nanoparticles were dispersed into different solvents to examine their applicability to silver ink. The silver ink using propylene glycol solvent showed good applicability to silver ink which could work at room temperature.