Synthesis, Characterization, and Catalytic Applications of Core–Shell Magnetic Carbonaceous Nanocomposites

Magnetic resorcinol/formaldehyde resin (RF) and silica/RF nanocomposites with well-defined core–shell architecture and tunable structural parameters had been prepared via the extended Stöber method. The carbon counterparts with similar structure and morphology can be obtained by thermal-treating the polymer precursors under N 2 atmosphere. The prepared materials were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Mössbauer spectroscopy, N 2 physical adsorption/desorption, and thermogravimetric analysis. The catalytic applications of the synthesized magnetic nanocomposites were also explored. It has been shown that the magnetite core was oxidized to γ-Fe 2 O 3 during polymer coating process and further reduced to original Fe 3 O 4 phase during carbonization. In addition, the iron oxide core can react with the shell when carbonization temperature reaches 700 °C. The structural stability of magnetic silica/RF is superior to magnetic RF because of the existence of an inner silica shell. Through a simple deposition–precipitate method, active platinum nanoparticles can be loaded in high dispersity onto the surface of the nanocomposites. The constructed magnetic catalysts are very active in hydrogenation of nitroarenes to corresponding amines and can be separated facilely with an external magnetic field.