Hydrophobic carbon nanotubes for removal of oils and organics from water

In this work, we synthesized p-phenylenediamine modified carbon nanotubes (P-CNTs) by diazotization reaction. The resulting material shows a BET surface area of 285 m2 g−1 and a total volume of 0.65 cm3 g−1 with abundant mesopores. Also, the P-CNTs exhibit good surface hydrophobicity with water contact angle of 140.8°, which should be attributed to the cooperation of both surface roughness and hydrophobic chemical compositions (aromatic rings linkages) of P-CNTs. Taking advantages of the intrinsic porosity and surface hydrophobicity, the resulting P-CNTs exhibit a notably selective absorbing ability and good recyclability for removal of organics and oils from water, which makes them the promising candidates for liquid–liquid separation and waste oil treatment.