Efficient growth of millimeter-long few-walled carbon nanotube forests and their oil sorption

Millimeter-long few-walled carbon nanotube (FWNT) forests were grown by a water-assisted chemical vapor deposition method. In only 10 min, the forests grew to over 1.2 mm in height, with a growth yield around 2.76 +/- 0.30 mg/cm(2). Transmission electron microscopy observation and Raman analysis showed high crystallinity of the nanotubes. A carbon purity better than 98.8 wt% was further determined by thermogravimetric analysis measurement. The FWNT forests were evaluated as an adsorbent for oil sorption and exhibited reasonable oil sorption capacity of 35 g/g. It is inferred that the oil sorption for CNT forests does not depend on their surface area.