Biopolymer assisted synthesis of metal-silica hybrid nanoflowers as a medium for the photocatalytic degradation of dye pollutants

This report presents an ecofriendly synthesis and characterization of biopolymer (sodium alginate)-capped silver nanoparticle-silicon dioxide (Ag-SiO2) hybrid nanoflowers and their efficiency for the plasmon-mediated dye degradation of methylene blue. The reducing and capping agents for the initial silver nanoparticles (AgNPs) synthesis were glucose and sodium alginate, respectively. The mesoporous silica nanostructures were introduced using two-step hydrolysis followed by a polycondensation process. Detailed structural and morphological characterizations of the as-prepared hybrid nanostructures were done using various techniques. The results revealed the formation of nanoflower-like hybrid alginate-capped Ag-SiO2 nanostructures with a size range of approximately 523 +/- 56 nm. The BET surface area analysis showed that the hybrid nanostructure has a surface area of 15.6 m2/g together with a pore diameter of 18.2 nm. The hybrid Ag-SiO2 nanoflowers showed excellent catalytic properties for the visible light photodegradation of methylene blue dye after 1 min exposure compared to silver nanoparticles at the same condition. The synergistic effect of SiO2 and Ag nanoparticles improved the catalytic property of the hybrid nanostructure. This study demonstrated a simple and effective model for the efficiency of designed hybrid nanostructures for degradation of industrial dyes.