فهرست مطالب sijo francis

Green alternatives prevail over the hazardous and expensive pathways of nanoparticles synthesis. Here we report eco-friendly manufacturing of gold nanoparticles by microwave assistance. The water soluble organic constituents of the tropical herb Elephantopus scaber functioned as the three electron donor and the aggregation preventer. XRD spectra certified fcc crystal lattice and the TEM images supported mixed spherical and triangular geometry to the nanoparticles with an average particle size of 18.97±5.86 nm. Ecological relevance of the gold nanoparticles lies in their ability to degrade methylene blue and methyl orange. The catalytic capacity of the gold nanoparticles is exploited in the reduction of 4-nitrophenol. Large scale production of gold nanoparticles in an easy manner using renewable sources improves the ‘green’ significance of the present synthesis.

Here we reported the extremely simple one-pot synthesis of silver and gold nanoparticles in a rapid manner. Aqueous leaf extract of the most admired energy plant Jatropha curcas is used as reducing agent here. An alternate and safe energy source, house-hold microwave oven constituted the reaction chamber. Silver and gold nanoparticles were characterized by UV-visible, FT-IR, Powder XRD techniques. Surface plasmon resonance peaks corresponding to silver and gold nanoparticles were 428 nm and 543 nm respectively. The XRD patterns were indexed to reflections originated from (111), (200), (220) and (311) faces of FCC nanosilver and nanogold. Microscopic analysis revealed spherical geometry of silver nanoparticles with an average diameter 20.42±12.2 nm. Gold nanometals exhibited uneven shapes with average size 17.12±2.9 nm. In-vitro antioxidant potential assessment by DPPH model gave IC50 values 19.37±0.63 and 16.59±0.29 µg/ mL for silver and gold nanoparticles. The nanometals showed excellent bactericidal activity in agar well diffusion towards microorganisms namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus nidulans and Aspergillus flavus. Degradation of methylene blue and rhodamine B by NaBH4 happened within 10 minutes in the catalytic presence of silver/gold nanoparticles offered a new means for purification of industrial dye effluents. Hydrogenation of 4-nitrophenol in presence of the prepared nanoparticles validated their catalytic utility. The reaction followed pseudo-first order kinetics with respect to reactant concentration.