Adsorption of Cu(II) on Oxidized Multi-Walled Carbon Nanotubes in the Presence of Hydroxylated and Carboxylated Fullerenes

Abstract

The adsorption of Cu(II) on oxidized multi-walled carbon nanotubes (oMWCNTs) as a function of contact time, pH, ionic strength, temperature, and hydroxylated fullerene (C60(OH)n) and carboxylated fullerene (C60(C(COOH)2)n) were studied under ambient conditions using batch techniques. The results showed that the adsorption of Cu(II) had rapidly reached equilibrium and the kinetic process was well described by a pseudo-second-order rate model. Cu(II) adsorption on oMWCNTs was dependent on pH but independent of ionic strength. Compared with the Freundlich model, the Langmuir model was more suitable for analyzing the adsorption isotherms. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggested that Cu(II) adsorption on oMWCNTs was spontaneous and endothermic. The effect of C60(OH)n on Cu(II) adsorption of oMWCNTs was not significant at low C60(OH)n concentration, whereas a negative effect was observed at higher concentration. The adsorption of Cu(II) on oMWCNTs was enhanced with increasing pH values at pH < 5, but decreased at pH ≥ 5. The presence of C60(C(COOH)2)n inhibited the adsorption of Cu(II) onto oMWCNTs at pH 4–6. The double sorption site model was applied to simulate the adsorption isotherms of Cu(II) in the presence of C60(OH)n and fitted the experimental data well.

Adsorption of Cu (II) ions from water by carbon nanotubes oxidized with UV-light and ultrasonication

“…Kosa et al used MWCNT modified with 8-hydroxyquinoline and they reached 100% of Cu (II) adsorption efficiency and 0.080 mg/g of adsorption uptake [19]. Wang et al prepared oxidized multi-walled carbon nanotubes in the presence of hydroxylated and carboxylated fullerenes, and they found the Cu (II) ion uptake as 33.97 mg/g [20]. Sitko et al used another carbonaceous material, graphene oxide for heavy metal adsorption.…”

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

“…Similarly, the band showing the presence of C�O groups in -COOH appears at around 1627 cm −1 . Wang et al [22], Li et al [25], and Moosa et al [30] found similar characteristic bands for the surface-modified CNTs.…”

“…erefore, the removal of copper from water is an essential study. Regarding the removal of Cu(II) with CNTs, many studies conducted so far have shown comparatively low values of maximum Cu(II) adsorption capacity [22][23][24][25][26][27][28]. e carbon nanotubes are known as an excellent adsorbent for heavy metals [29][30][31][32].…”

The Changes of Absorption and Catalytic Capacity on Reduced Graphene Oxide After Electron Beam Irradiation

“…Moreover, the -stacking between aromatic structure of dyes and sp 2 regions of R-GO, as well as the electrostatic interactions between charged organics or metal ions and the surface oxygen-containing groups of R-GO might also assist in the adsorption. 33,34 As is well-known, the interaction …”

“…34 Therefore, compared with R-RGO, the more C structure of the R-GO made it have a larger maximum adsorption amount for gallic acid, but the less surface area made its adsorption rate decrease.…”