Fe@C core–shell and Fe@C yolk–shell particles for effective removal of 4-chlorophenol

Fe@C core–shell particles were successfully synthesized by coating Fe2O3 particles with resorcinol–formaldehyde resins (RFs) and then calcining to make the RFs carbonize, and at the same time to reduce the core to Fe. Furthermore, we designed and synthesized Fe@C yolk–shell particles to increase the number of active sites on the Fe surface. Compared with pure Fe material, the Fe in these particles possesses a high surface area without serious aggregation. Tests to remove 4-chlorophenol suggest that both these kinds of particles can degrade chlorophenol rapidly and thoroughly based on a Fenton-like reaction. Using Fe@C yolk–shell particles, the chlorophenol can be degraded to a concentration below the HPLC detection limit (<0.5 mg l−1) within 12 minutes. The magnetic properties and good stability of Fe@C endow it with promising potential for water treatment.