Carbon nanotubes as sorbent material for removal of cadmium

Abstract

Heavy metal ions are highly toxic industrial pollutants of which maximum levels are regulated such as in the ppb range for drinking water. Elevated levels of heavy metals in natural water may have a detrimental effect on both human health and the environment. Carbon nanotubes (CNTs) have been investigated widely over last two decades for numerous potential applications to exert considerable technological impact on future miniaturized, compact, cost effective, and efficient devices. The novel tubular structures of CNTs became one of the most valuable materials in water management due to their distinct features such as inertness, porous structure, low density, and affinity for pollutants. Such astonishing features help make them overcome the shortcomings of activated carbon. In this research, we focused on the synthesis, characterization, and evaluation of multi walled carbon nano tubes (MWCNTs) as adsorbent for removal of cadmium. MWCNTs synthesized in size range of 60-70 nm (width) and length in microns using chemical vapour deposition (CVD) method were characterized by the field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Raman spectroscopic analyses. These MWCNTs when explored for the removal of cadmium ions (Cd2+) from their aqueous solutions exhibited a maximum adsorption capacity of 181.8 mg/g with the Langmuir isotherm model (R-2 = 0.98). The findings of this research work project that CNTs can play a vital role as nanoadsorbent towards heavy metals management.