Research Article

Carbon Nanotubes: Synthesis via Chemical Vapour Deposition without Hydrogen, Surface Modification, and Application

Table 2

Isotherm parameters calculated from the Langmuir model of Cu(II) adsorption onto many kinds of surface-modified CNTs.

Sorbentsqm (mg·g−1)R2References

CNTs ultrasonically stirred in KMnO4 and H2SO4163.70.995The present study
CNTs refluxed in the solution of HNO3 and H2SO4 at 80°C for 48 h29.690.980[22]
CNTs refluxed in 65% HNO3 at 120°C for 48 h2000.998[23]
MWCNTs ultrasonically stirred in 3 M HNO3 for 24 h3.4390.932[24]
CNTs refluxed in concentrated HNO3 for 1 h at 140°C28.490.991[25]
MWCNTs ultrasonically suspended in 3 M HNO3 for 30 min and then stirred at 110°C for 48 h530.994[26]
CNTs ultrasonically immersed in 65% HNO3 for 30 min and then stirred for 3 h at 298 K13.870.980[27]
CNTs ultrasonically immersed in 60% NaClO for 30 min and then stirred for 3 h at 358 K47.390.987[27]
CNTs ultrasonically dispersed in 23% HCl and then stirred on a hot plate at 175°C–200°C for 3 h6.2350.973[28]