Eco‐Friendly Synthesis of Iron Nanoparticles Using Green Tea Extract: Characterization and Evaluation of Their Catalytic, Anti‐oxidant and Anti‐bacterial Potentials

Abstract

The green route for the synthesis of metal nanoparticles has emerged as a promising pathway due to its simple, non‐toxic, low‐cost, and environment‐friendly nature. In this study, eco‐friendly iron nanoparticles were successfully synthesized from the extract of green tea leaves. The synthesized nanoparticles were characterized by UV‐Visible, FT‐IR, SEM, EDX, TEM, and XRD techniques. The morphological analysis of the nanoparticles by SEM and TEM studies revealed that they were spherical in shape with particle size in the 30–70 nm range. The XRD investigation established the amorphous nature of the nanoparticles. The role of the phytochemicals of the tea extract as the reducing and stabilizing agents for the nanoparticles was confirmed by the FT‐IR analysis. The iron nanoparticles exhibited significant catalytic potential in the degradation of organic dyes‐ malachite green and methylene blue. The reactions followed pseudo‐first‐order kinetics and the percent degradation of 85.20 % for malachite green and 89.42 % for methylene blue was achieved in 20 min. and 10 min. respectively. The nano‐catalyst was reusable for three consecutive cycles of degradation reaction without any significant loss in its activity. The anti‐oxidant activity of the nanoparticles was studied by the DPPH assay wherein the nanoparticles exhibited a promising free radical scavenging ability of about 77 % with the IC50 value of 589.70 μg/mL. The anti‐bacterial activity of the nanoparticles was analyzed by the agar well diffusion method against four bacterial strains: gram‐positive Staphylococcus aureus, Bacillus subtilis, and gram‐negative Escherichia coli, Pseudomonas aeruginosa. The zones of inhibition and the Minimum Inhibitory Concentration (MIC) values of the nanoparticles were determined. The nanoparticles showed moderate toxicity against all the tested bacterial strains. The synthesis of the iron nanoparticles was rapid and simple and the results of the investigated applications were significant and promising.

Improved Photocatalytic and Antibacterial Activity of Mg0.33Ni0.33Co0.33GdxFe2‐xO4 Nanoparticles Synthesized via the Co‐precipitation Method

“…On the other hand, E. coli and S. aureus didn't show any inhibitory activity against the tested NPs. These results are similar to several studies, performed on Ag‐doped magnesium nano‐ferrites and Iron NPs, which tested the susceptibility of similar bacteria to the ones tested in this work, especially E. coli and S. aureus [47b,55] . The agar well diffusion results are shown in Table 5 and Figure S6 in the Supporting Information.…”