TY - JOUR
T1 - Adsorption of Cd 2+ on carboxyl-terminated superparamagnetic iron oxide nanoparticles
AU - Feng, Zhange
AU - Zhu, Shun
AU - Martins De Godoi, Denis Ricardo
AU - Samia, Anna Cristina S.
AU - Scherson, Daniel Alberto
PY - 2012/4/17
Y1 - 2012/4/17
N2 - The affinity of Cd 2+ toward carboxyl-terminated species covalently bound to monodisperse superparamagnetic iron oxide nanoparticles, Fe 3O 4(np)-COOH, was investigated in situ in aqueous electrolytes using rotating disk electrode techniques. Strong evidence that the presence of dispersed Fe 3O 4(np)-COOH does not affect the diffusion limiting currents was obtained using negatively and positively charged redox active species in buffered aqueous media (pH = 7) devoid of Cd 2+. This finding made it possible to determine the concentration of unbound Cd 2+ in solutions containing dispersed Fe 3O 4(np)-COOH, 8 and 17 nm in diameter, directly from the Levich equation. The results obtained yielded Cd 2+ adsorption efficiencies of ∼20 μg of Cd/mg of Fe 3O 4(np)-COOH, which are among the highest reported in the literature employing ex situ methods. Desorption of Cd 2+ from Fe 3O 4(np)-COOH, as monitored by the same forced convection method, could be accomplished by lowering the pH, a process found to be highly reversible.
AB - The affinity of Cd 2+ toward carboxyl-terminated species covalently bound to monodisperse superparamagnetic iron oxide nanoparticles, Fe 3O 4(np)-COOH, was investigated in situ in aqueous electrolytes using rotating disk electrode techniques. Strong evidence that the presence of dispersed Fe 3O 4(np)-COOH does not affect the diffusion limiting currents was obtained using negatively and positively charged redox active species in buffered aqueous media (pH = 7) devoid of Cd 2+. This finding made it possible to determine the concentration of unbound Cd 2+ in solutions containing dispersed Fe 3O 4(np)-COOH, 8 and 17 nm in diameter, directly from the Levich equation. The results obtained yielded Cd 2+ adsorption efficiencies of ∼20 μg of Cd/mg of Fe 3O 4(np)-COOH, which are among the highest reported in the literature employing ex situ methods. Desorption of Cd 2+ from Fe 3O 4(np)-COOH, as monitored by the same forced convection method, could be accomplished by lowering the pH, a process found to be highly reversible.
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U2 - 10.1021/ac300392k
DO - 10.1021/ac300392k
M3 - Article
C2 - 22428526
AN - SCOPUS:84859913089
VL - 84
SP - 3764
EP - 3770
JO - Industrial And Engineering Chemistry Analytical Edition
JF - Industrial And Engineering Chemistry Analytical Edition
SN - 0003-2700
IS - 8
ER -