A novel and eco-friendly route for the synthesis of porous CeO2 microstructure is reported. The citric acid mediated economical route is developed for the synthesis of a three-dimensional (3D) flowerlike micro/nanocomposite structure. Materials were characterized by a complementary combination of X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS). CeO2 samples obtained have remarkably high surface area when compared to the commercial CeO2 sample. The surface area of CeO2 sample decreased upon calcination at higher temperature. However, the surface area is still almost 20 times more when compared to the commercial CeO2 sample. TEM investigation reveals that upon calcination at higher temperature, the size of the crystal increased but the short range order was merely disturbed. The analyses shows that the present method is suitable as a direct route for synthesizing nanoporous CeO2. Micro/nanocomposite CeO2 was found to be an excellent sorbent for the removal of poisonous pollutants present in water, such as arsenic (As) and chromium (Cr). (C) 2010 Elsevier Inc. All rights reserved.