Magnetic nanoparticles have been widely investigated due to their environmental and biomedical applications. However, the unavoidable problems associated with them are their intrinsic instability and the trend of the agglomeration. Mesoporous carbon is considered as an ideal matrix for the protection of magnetic nanoparticles owing to its high surface area, excellent chemical and thermal stability. The preparation of morphology defined composites of magnetic nanoparticles and mesoporous carbon is of great importance for their practical applications. In this work, magnetic mesoporous graphitic composites (MMGCs) with defined rhombododecahedral morphology are fabricated by the pyrolysis of the composites from the hierarchical co-assembly of amphiphilic triblock copolymer, resol oligomers and Fe3O4 nanoparticles. MMGCs exhibit narrow bimodal pore size distribution, high surface area and highly stable magnetic properties, which provide them excellent adsorption ability for the removal of organic contaminants in aqueous solution. (C) 2013 Elsevier Inc. All rights reserved.