Green Synthesis Of Iron Based Nanoparticles Using Green Tea Extract And For Its Degradation Of Malachite Green

Iron nanoparticles (Fe NPs) have attracted much attention in environmental remediation due to their nanoscale, chemical, catalytic, electrical, magnetic, mechanical and optical properties. Conventional synthesis of Fe NPs include chemical and physical methods, but limitations include high cost (high temperature and pressure in the physical method) and environmental hazardous (many toxic chemics were used in the chemical methods). Consequently, a large scale of site remediation is impossible. Therefore, it is required to develop a low cost and environmental friendly method of synthesis Fe NPs.In this thesis, Fe NPs were synthesized using green tea extract (GTE), oolong tea extract (OTE) and black tea extract (BTE) as reductant and their application in removing malachite green (MG). The results showed that the removal rate of MG removed by Fe NPs synthesized using GTE (GT-Fe NPs) after 60 min was 81.56%,75.56% by Fe NPs produced using OTE (OT-Fe NPs) and 67.06% by Fe NPs formed using BTE (BT-Fe NPs). Through scanning electron microsope (SEM), x-ray energy anlysis (EDS) and x-ray diffraction (XRD) characterization techniques, these Fe NPs were spherical and amorphous with the diameter range from 20 nm-80 nm. Moreover, fourier transform infrared spectroscopy (FTIR) confirmed that polyphenol and caffeine from tea extract acted as reducing and capping agent in process of synthesis Fe NPs. With the characterization and removal experiments of malachite green, GT-Fe NPs were more dispersive and active among GT-Fe NPs, OT-Fe NPs and BT-Fe NPs.To further improve the dispersion and stability of Fe NPs, conditions impacting on the reactvity of Fe NPs with malachite green (MG) by green tea extract were investigated, including the volume ratio of Fe2+ and tea extract, the solution pH, temperature and surfactants. The results showed that the highest reactivity of Fe NPs used for the degradation of MG under the conditions such as the ratio of green tea extract and Fe2+ was 1:1. Further various surfactants as the stabilizer were examined, where 0.002 mol/L of cetyl trimethyl ammonium bromide (CTAB) improved the dispersion and reactivity of Fe NPs synthesized using green tea extract. This indicate CTAB can be acts as an excellent template to regulate the Fe NPs growths and hence to control the dispersion and reactivity of Fe NPs.