• Sodium citrate
  • Silver nitrate
  • Ceramic evaporator and spoon
  • Beaker (150 cm3)

The Ag hydrosol preparation was carried out by a chemical reduction of silver nitrate by sodium citrate. An aliquot of 3.0 or 4.5mL of an aqueous solution of sodium citrate (10 mg/mL) was added drop-wise into 150 mL of a bowling and stirred aqueous solution of silver nitrate of 0.18 mg/mL concentration. After addition, the resulting hydrosol was further boiled for 10–15 min. The hydrosol was stirred for more than 15 min and, after that, diluted with water to get a total volume of 126 mL.