Carbon nanotube sponge soaks up contaminants

The carbon nanotube (CNT) sponges, doped with sulphur, also demonstrated a high capacity to absorb oil. The results have been published in Nanotechnology.

CNTs are hollow cylindrical structures composed of a single sheet of carbon that have been proposed as suitable candidates for wastewater clean-up. However, problems have arisen when trying to handle the fine powders and eventually retrieve them from the water.

In a statement lead author of the research Luca Camilli, from the University of Roma, said: ‘It is quite tricky using CNT powders to remove oil spilled in the ocean. They are hard to handle and can eventually get lost or dispersed in the ocean after they are released.

‘However, millimetre- or centimetre-scale CNTs, as we’ve synthesised in this study, are much easier to handle. They float on water because of their porous structure and, once saturated with oil, can be easily removed. By simply squeezing them and releasing the oil, they can then be re-used.’