A highly efficient and versatile carbon nanotube/ceramic composite filter

Carbon nanotubes were grown in the open pores of a commercial porous ceramic matrix consisting of mainly Al2O3 and SiO2 with an average pore size of 300 and 500 μm, using a pre-formed nickel catalyst inside the pores and a camphor solution precursor at 780 °C. The resulting composites, ∅27 mm × 10 mm discs containing about 3 wt.% of carbon nanotubes, were then assessed as a filter for the removal of yeast cells and different heavy metal ions from water, and for the removal of particulates from air. The results showed that the carbon nanotube containing composite filter demonstrated a high efficiency of yeast filtration (98%), ca. 100% heavy metal ion removal from water and excellent particulate filtration from air. The composite filter also exhibited good reusability for these applications, owing to the excellent thermal and chemical stability of the carbon nanotubes.