BACKGROUND: Remediation of oil spillage accidents requires efficient and low cost floating absorbents to remove small amounts of contaminant oil. In this work, a highly hydrophobic floating magnetic macroporous structure based on silica encapsulated Fe nanoparticles was prepared and used for oil absorption from water. RESULTS: The magnetic macroporous materials were prepared by silica encapsulation of iron oxide/hydroxide nanoparticles followed by a thermal treatment with H-2. Mossbauer, XRD, SEM/TEM, CHN, IR, TG/DTA and contact angle analyses showed that the Fe oxides nanoparticles are reduced by H-2 to formFeo cores protected by silica which sinters to form a macroporous network. The surface reaction with octadecyltrimethoxysilane (Si(CH3O)(3)C18H37) was used to produce highly hydrophobic materials. CONCLUSIONS: The materials obtained showed very high oil absorption capacities for different model contaminants, i.e. petroleum, soy bean oil, diesel, gasoline and xylene removal. The results are discussed in terms of a macroporous structure with strong capillarity combined with a very hydrophobic surface. (C) 2015 Society of Chemical Industry