Green synthesis of silver nanoparticles (AgNPs) and its application for photocatal ytic activation of methylene blue / Nur Diyana Syazwani Zambri

The silver nanoparticles (AgNPs) were successfully synthesized by green route method using aqueous extract of Azadirachta Indica and silver nitrate solution. The effect of various parameters which are extracted volume of Azadirachta Indica leaf extract with reaction time and concentration of silver nitrate with reaction time were studied. It was found that hydroxyl and carboxylate groups of the aqueous leaf extract play major role for the formation of AgNPs through infrared spectra analysis. The most suitable extracted volume and silver nitrate concentration for formation of AgNPs were found to be at 3 mL and 1 mM respectively through UV-Vis analysis. Besides, the shape were mostly spherical and oval in shape. The size diameter range were noted from 30 to 80 nm with the average diameter of selected area in the SEM image was 70 nm. The strong signal and the sharp peak of silver atom in the EDX analysis also gives a clear indication of the presence of elemental silver in the sample with the weight percentage of 56.12 %. This study also revealed that the silver nanoparticles can be an excellent photocatalyst on reduction of methylene blue dye which was confirmed by the gradual decrease of maximum absorbance values at 664 nm when exposed to direct sunlight compared UV-A lamp irradiation that shows slower rate of degradation as recorded by UV-Vis spectrum

Utilization of Neem Leaf Extract on Biosynthesis of Iron Oxide Nanoparticles

The present work reports the successful synthesis of biosynthesized iron oxide nanoparticles (Fe3O4-NPs) with the use of non-toxic leaf extract of Neem (Azadirachta indica) as a reducing and stabilizing agent. The successful synthesis was confirmed by infrared spectra analysis with strong peak observed between 400–600 cm−1 that corresponds to magnetite nanoparticles characteristics. X-ray diffraction (XRD) analysis revealed that iron oxide nanoparticles were of high purity with crystalline cubic structure phases in nature. Besides, the average size of magnetite nanoparticles was observed to be 9–12 nm with mostly irregular shapes using a transmission electron microscope (TEM) and was supported by field emission scanning electron microscope (FESEM). Energy dispersive X-ray analysis shown that the elements iron (Fe) and oxygen (O) were present with atomic percentages of 33.29% and 66.71%, respectively. From the vibrating sample magnetometer (VSM) analysis it was proven that the nanoparticles exhibited superparamagnetic properties with a magnetization value of 73 emu/g and the results showed superparamagnetic behavior at room temperature, suggesting potential applications for a magnetic targeting drug delivery system