Synthesis and Analytical Characterization of Gold Nanoparticles using Microwave-Assisted Extraction System and Study their Application in Degradation

Abstract

Preparation of gold nanoparticles (AuNPs) was done by the addition of tetrachloroaurate (HAuCl4) to dodonaea viscose (L.) leaves watery extract. The procedure was performed in microwave-assisted extraction (MAE). Dodonaea viscose (L.) watery extract functions as a reducing and capping agent to synthesis AuNPs. The gold nanoparticles was identified by the changes in colour from yellow to red –purple, UV-vis spectroscopy, and surface plasmon band at (600 nm). (EDX -FESEM) and TEM instruments were used to investigate the element analysis, distribution of nanoparticles and to calculate their sizes and shapes. Energy dispersive X-ray spectra (EDX) was applied for characterization of gold nanoparticles, the detected percentage of gold nanoparticles was (0.52 wt/wt %). The result from TEM shows the nanoparticles with diameter (6-80 nm) and vary shapes. Furthermore, characterization of nanoparticles was performed before and after the formation of gold nanoparticles using FT-IR. The band appeared at 669 cm-1 indicated the gold nanoparticle formation. The synthesized gold nanoparticles have been used for degradation of 6.6 % methylene blue organic dye pollutant in aqueous solution, and also for degradation of aliphatic hydrocarbons in crude oil. The results of degradation were monitored by GC-MS. The breakage of some organic materials and the appearance of new organic materials with less molecular weight and less abundance were achieved. Through the use of gold nanoparticles, it has been observed that a large number of aliphatic compounds have disappeared, especially those with molecular weights 200-288, the loss in the molecular weight is about 40%.