2. Experimental
2.1 Materials and reagents
Pyrrole (Spectrochem Pvt. Ltd, Mumbai) was double distilled and stored in refrigerator before use. Ferric Chloride (anhydrous) and trisodium citrate were procured from S. D. Fine Chem. Ltd., Mumbai. Silver Nitrate was purchased from Research Lab Fine Chem. Industries, Mumbai. These chemicals were of AR grade and were used as received. All solutions of reacting materials were prepared in distilled water.
2.2 Synthesis of Polypyrrole
Polypyrrole (PPy) was synthesized by chemical oxidative polymerization technique. 1M Pyrrole solution was prepared using distilled water. This mixture was then cooled to ~ 0°C in an ice bath and stirred on a magnetic stirrer for 30 minutes. The 1M solution of FeCl3 (oxidizing agent), was prepared using distilled water, precooled and then added drop wise into the pyrrole solution. The oxidant to monomer ratio 2.5:1 was maintained. Then the polymerization was conducted for 5 hours under constant stirring. This mixture was allowed to settle for 24 hours to ensure complete polymerization. The polypyrrole powder was filtered under reduced pressure and washed with distilled water several times to remove the unreacted monomer, oxidant and ferric or ferrous contamination and was dried under vacuum at room temperature.…show more content… In typical experiment 60 ml of 1 mM AgNO3 was heated to boil. To this solution 6 mL of 10 mM trisodium citrate was added dropwise, about 1 drop per second. During the process, solutions were mixed vigorously and heated. The color of the solution slowly turned into golden yellow, indicating formation of silver nanoparticles [21]. Heating was continued for an additional 15 min, and then the solution was cooled to room temperature. Large quantity of such solution was prepared and used as stock solution for other