Microwave Enhanced Synthesis of Silver Nanoparticles Using Orange Peel Extracts from Nigeria

Abstract

The gamut of applications for metal nanoparticles fuels the interest for their synthesis. The hazardous, time and energy consuming nature of conventional techniques necessitates the search for alternative methods of synthesis that ensures the desired size, shape and dispersity is achieved. The use of aqueous plant extracts to reduce toxic heavy metals is a spontaneous, cost effective, eco-friendly method used in the synthesis of nanoparticles. Microwave catalysis have also gained acceptance as another green method for material synthesis due to its high reaction rates and shortened reaction times. This study was embarked on to develop a rapid and eco-friendly method for synthesizing silver nanoparticles (AgNPs), stabilized within a biocompatible matrix using orange peel extracts, starch and a microwave. Data obtained revealed from the characterization of the synthesized AgNPs revealed that the surface plasmon resonance (SPR) peaked at 408nm using a UV-Visible Spectrophotometer. The EDX spectrum of the solution containing silver nanoparticles confirmed the presence of an elemental silver signal. SEM and HR-TEM images suggest that the nanoparticles were of spherical shape. HR- TEM particle size range was 7-17.31±0.84nm. FT-IR spectroscopy analysis of synthesized AgNPs indicated a slight shift at the O-H absorption bands of starch. PXRD confirmed the reflections of silver nanoparticles at corresponding 2θ values respectively. The results obtained suggested that rapid catalysis of AgNPs using plant extracts is further boosted using microwave enhanced catalysis whereby the functional biomolecules from the plant extract is retained, altogether forming stable AgNPs.