Effect of acid and alcohol network forces within functionalized multiwall carbon nanotubes bundles on adsorption of copper (II) species

► Network forces in oxygen functionalized MWCNTs are contributors to adsorption capacity. ► Alcohol functionalized MWCNTs have better adsorption capacity than acid functionalized MWCNTs. ► Adsorption capacity acid functionalized MWCNT can be improved by strong-base washing. ► Removal of impurities did not improve the effect of initial concentration. ► The constant electronegativity of functionalized MWCNT makes them good sorbents.