High value products from waste: grape pomace extract--a three-in-one package for the synthesis of metal nanoparticles.

Metal nanoparticles of Au, Ag, Pd, and Pt have been synthesized in aqueous media using red grape pomace as a reducing agent and a capping agent. The particles are formed within a few seconds when exposed to microwave irradiation at a power level as low as 50 W. Particles could be formed at room temperature, but they tend to be amorphous in nature except for gold. A detailed study on the morphology of the ensuing particles with various reaction conditions has been carried out.