Limits...
Adsorption of Cu(II) on oxidized multi-walled carbon nanotubes in the presence of hydroxylated and carboxylated fullerenes.

Wang J, Li Z, Li S, Qi W, Liu P, Liu F, Ye Y, Wu L, Wang L, Wu W - PLoS ONE (2013)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Radiochemistry Laboratory, School of Nuclear Science and Technology, Lanzhou University, Lanzhou, PR China.

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.

Show MeSH

Related in: MedlinePlus

TEM photographs of (A) oMWCNTs; (B) oMWCNTs+C60(OH)n; (C) oMWCNTs +C60(C(COOH)2)n.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3756995&req=5

pone-0072475-g001: TEM photographs of (A) oMWCNTs; (B) oMWCNTs+C60(OH)n; (C) oMWCNTs +C60(C(COOH)2)n.

Mentions: Figure 1 shows TEM photomicrographs of oMWCNTs, C60(OH)n-oMWCNTs dispersion, and C60(C(COOH)2)n-oMWCNTs dispersion in aqueous solution, respectively. Carbon nanotubes (Figure 1A) have an integrated hollow tubular structure after oxidation, indicating that their surfaces are smooth, without any obvious amorphous carbon and other particles on their walls. For the sample of C60(OH)n-oMWCNTs dispersion (Figure 1B), some particles (seen the represent of arrow in Figure 1B) persisted on the walls of CNTs. It can be discerned that C60(OH)n particles are heterogeneously attached to the surface of oMWCNTs. As can be seen from Figure 1C, the surface of oMWCNTs are not coated with C60(C(COOH)2)n. This may be attributed to differences in functional substitution on the surface of C60.


Adsorption of Cu(II) on oxidized multi-walled carbon nanotubes in the presence of hydroxylated and carboxylated fullerenes.

Wang J, Li Z, Li S, Qi W, Liu P, Liu F, Ye Y, Wu L, Wang L, Wu W - PLoS ONE (2013)

TEM photographs of (A) oMWCNTs; (B) oMWCNTs+C60(OH)n; (C) oMWCNTs +C60(C(COOH)2)n.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756995&req=5

pone-0072475-g001: TEM photographs of (A) oMWCNTs; (B) oMWCNTs+C60(OH)n; (C) oMWCNTs +C60(C(COOH)2)n.
Mentions: Figure 1 shows TEM photomicrographs of oMWCNTs, C60(OH)n-oMWCNTs dispersion, and C60(C(COOH)2)n-oMWCNTs dispersion in aqueous solution, respectively. Carbon nanotubes (Figure 1A) have an integrated hollow tubular structure after oxidation, indicating that their surfaces are smooth, without any obvious amorphous carbon and other particles on their walls. For the sample of C60(OH)n-oMWCNTs dispersion (Figure 1B), some particles (seen the represent of arrow in Figure 1B) persisted on the walls of CNTs. It can be discerned that C60(OH)n particles are heterogeneously attached to the surface of oMWCNTs. As can be seen from Figure 1C, the surface of oMWCNTs are not coated with C60(C(COOH)2)n. This may be attributed to differences in functional substitution on the surface of C60.

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Radiochemistry Laboratory, School of Nuclear Science and Technology, Lanzhou University, Lanzhou, PR China.

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.

Show MeSH
Related in: MedlinePlus