The lightweight, porous structure and excellent hydrophobicity/oleophilicity of CA make it an ideal candidate for highly efficient separation/extraction of specific substances, such as organic pol-lutants and oils. The high sorption capacities of oils and organic solvents by using CAs exhibited in Fig. 5a–c. As shown in Fig. 5a,once brought into contact with a pump oil layer (dyed with SudanIII) on a water surface, a small piece of CA can absorb pump oilselectively and completely in several seconds. Because of the lowerdensity of pump oil than water, the low density, and hydrophobicnature of CA, the CA can float on the water surface after collecting allpump oil, indicating its potential use for cleaning up oil spillage and chemical leakage.