Biomolecule-entrapped SiO2 nanoparticles for ultrafast green synthesis of silver nanoparticle-decorated hybrid nanostructures as effective catalysts

Noble-metal hybrid nanostructures have gained tremendous attention due to their potential roles in biomedical and catalytic applications. In this study, for the synthesis of silver nanoparticles (Ag NPs)-silica (SiO2) NPs, a novel green chemistry approach was employed, in which green tea biomolecule-encapsulated SiO2 nanostructures were used for the reduction of silver ions to produce hybrid nanostructures within 300 s. The high-resolution transmission electron microscopy (HrTEM) revealed the formation of uniform ultrafine spherical Ag NPs that were evenly distributed in the nanostructures. The formed nanohybrid structures showed efficient catalytic activity for the formation of derivatives of dihydroquinoline, and retained 91% of their reusability capacity, even after 5 repeated cycles. Hence, this work provides a novel synthesis method not only for the synthesis of biomolecule-entrapped SiO2 nanostructures, but also for the rapid formation of catalytically active hybrid nanostructures.