Facile preparation of carbon coated magnetic Fe3O4 particles by a combined reduction/CVD process

In this work, we report a simple method for the preparation of magnetic carbon coated Fe3O4 particles by a single step combined reduction of Fe2O3 together with a Chemical Vapor Deposition process using methane. The temperature programmed reaction monitored by Mössbauer, X-ray Diffraction and Raman analyses showed that Fe2O3 is directly reduced by methane at temperatures between 600 and 900 °C to produce mainly Fe3O4 particles coated with up to 4 wt% of amorphous carbon. These magnetic materials can be separated into two fractions by simple dispersion in water, i.e., a settled material composed of large magnetic particles and a suspended material composed of nanoparticles with an average size of 100–200 nm as revealed by Scanning Electron Microscopy and High-resolution Transmission Electron Microscopy. Different uses for these materials, e.g., adsorbents, catalyst supports, rapid coagulation systems, are proposed.

Graphical abstractMagnetic carbon coated Fe3O4 particles are prepared by a one step combined reduction of Fe2O3 together with a CVD process of using methane. Analyses show that the Fe2O3 is reduced by methane to produce mainly Fe3O4 particles coated with amorphous carbon. These materials can be separated into two fractions by simple dispersion in water and can be used as adsorbents, catalyst supports and rapid coagulation systems.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Magnetic Fe3O4 particles coated with a very thin layer of amorphous carbon (4 wt%). ► Combined reduction of Fe2O3 with a Chemical Vapor Deposition process using methane. ► Nanoparticles with an average size of 100–200 nm. ► Uses as adsorbent, catalyst support and rapid coagulation systems.