Abstract 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 . Mössbauer, XRD , SEM / TEM , CHN , IR , TG / DTA and contact angle analyses showed that the Fe oxides nanoparticles are reduced by H 2 to form Fe o cores protected by silica which sinters to form a macroporous network. The surface reaction with octadecyltrimethoxysilane (Si( CH 3 O ) 3 C 18 H 37 ) 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. © 2015 Society of Chemical Industry