Encapsulation of Ag nanoparticles in magnetically modified silica nanostructures for reduction of 4-nitrophenol

摘要

An Ag/Fe3O4@SiO2-APTES nanostructure was prepared for the reduction of 4-nitrophenol (organic pollutant), exhibiting excellent yield in a short time. Partial digestion of magnetite formed pseudo-hollow structures which could further activate the Ag for catalytic reaction. Encapsulation of Ag was able to avoid undesirable phenomena such as agglomeration of Ag nanoparticles and their leaching. A mesoporous organosilanes layer was able to facilitate the contact of organic reactant with the catalyst surface while the incorporated magnetite allowed easy separation of the catalyst for reuse. The reduction reaction was simple (ambient conditions), fast (10 min), clean (water as a solvent), green (without waste/by-product), with low loading of the catalyst (1 mg of Ag), producing high yields (99), and capable of almost 100 catalyst recovery.