In situ synthesis of silver nanostructures on magnetic Fe₃O₄@C core–shell nanocomposites and their application in catalytic reduction reactions

Abstract

In this article, a study was presented on the catalytic activity of silver nanoparticles immobilized on magnetic Fe3O4@C (MFC) core–shell nanocomposites (Ag/MFC) that were used as carriers. MFC composites consist of a magnetic core of an Fe3O4 microsphere onto which a thin layer of carbon was coated by in situ carbonization of glucose under hydrothermal conditions. The catalytic activity of the as-prepared Ag/MFC is investigated by photometrically monitoring the reduction of 4-nitrophenol and methylene blue by an excess of NaBH4. The kinetic data of both reduction reactions could be explained by the assumption of a pseudo-first-order reaction with regard to 4-nitrophenol or methylene blue. Significantly, the Ag/MFC catalysts can be easily separated from the reaction media by applying an external magnet, and can be reused for several cycles.