PREPARATION OF COLLOIDAL SILVER NANOPARTICLES AND ITS ACTIVITY TEST AS RHODAMIN B OXIDATION CATALYST

• Main Author: Fahmawati, Diah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/42278
• Institution: Institut Teknologi Bandung

Silver nanoparticles (AgNPs) have unique properties, that make it suitable for many applications such as sensors, catalysts, anti-bacteria and biomedicine. Physical and chemical properties of AgNPs are influenced by their particle size which in turn are determined by the reaction condition in which they are formed, for example pH, reducing and capping agent used. AgNPs have been reported to have good catalytic activity in the degradation of Rhodamine B (Rhd B) by persulfate, but its synthesis take long time and less efficient. AgNPs synthesis was carried out by chemical reduction method. In this study, fresh and cold NaBH4 aqueous solution was used as reducing agent and glutathione (GSH) as capping agent. Characterization of AgNPs was carried out by UV / Vis spectrophotometry, particle size analyzer (PSA), zeta potential, FTIR and HRTEM. The PSA measurement show that the greater the mol ratio of NaBH4 : AgNO3, the smaller the size of AgNPs. The particle size of AgNPs of 8.4 nm is obtained at the mole ratio of NaBH4: AgNO3 = 10 : 3 and pH = 9. The smallest size of AgNPs particles (1.7 nm) resulted as the pH of the solution increased to 10. AgNPs modified with glutathione produced by AgNPs the small one is 1.4 nm. The catalytic activity of AgNPs was measured by comparing the rate of discoloration of Rhodamin B affected by the addition of persulfate to that affected by the addition persulfate and AgNPs. The comparation showed that the addition of AgNPs increased the discoloration rate by a factor of 4. The oxidation reaction of Rhd B by persulfate is shown to be a quasi-first order reaction to the Rhd B concentrations. Analysis of HPLC and UPLC-MS showed the formation of benzoic acid, benzoic trihydroxy and isoindoline-1,3-dione as oxidation products of Rhd B.