Fabrication of Carbon-Coated Fe₃O₄-SnO₂ Core-Shell Nanocomposites via Surface Carboxylation and Amination

Nanocomposites with a core-shell structure composed of different materials can exhibit new physicochemical and electrical properties that will become the basis for future technology expansion. Magnetite (Fe₃O₄) with special magnetic, electrochemical properties and many other attributes has attracted attention in wide fields, such as medical science, separation technology, catalysis, energy storage, and electromagnetic absorption. Also, tin dioxide (SnO₂) with a large bandgap and high electron mobility has been widely used as a gas sensing, catalysis, dielectric material. So, a lot of research has been done to compound the two substances. However, Fe₃O₄/SnO₂ composed of oxides is difficult to realize high performance due to poor conductivity, so a method to overcome this is required. In this study, carbon-coated Fe₃O₄-SnO₂ nanocomposites with core-shell structures were prepared via surface functionalization and carbonization. An anionic surface modifier was used to decorate SnO₂ and silane/polymeric-based surface aminations were introduced to coat the carbon, respectively. Consequentially, a hydrophilic carbon was formed on the surface of Fe₃O₄-SnO₂ nanoparticles through dehydration of glucose using sulfuric acid at atmospheric pressure.