Functionalized Fe₃O₄@Silica Core-Shell Nanoparticles as Microalgae Harvester and Catalyst for Biodiesel Production

Core-shell Fe₃O₄@silica magnetic nanoparticles functionalized with a strong base, triazabicyclodecene (TBD), were successfully synthesized for harvesting microalgae and for one-pot microalgae-to-fatty acid methyl ester (FAME, or so-called biodiesel) conversion. Three types of algae oil sources (i.e., dried algae, algae oil, and algae concentrate) were used and the reaction conditions were optimized to achieve the maximum biodiesel yield. The results obtained in this study show that our TBD-functionalized Fe₃O₄@silica nanoparticles could effectively convert algae oil to biodiesel with a maximum yield of 97.1 %. Additionally, TBD-Fe₃O₄@silica nanoparticles act as an efficient algae harvester because of their adsorption and magnetic properties. The method presented in this study demonstrates the wide scope for the use of covalently functionalized core-shell nanoparticles for the production of liquid transportation fuels from algal biomass.