TY - JOUR
T1 - Sorption mechanisms of metals to graphene oxide
AU - Showalter, Allison R.
AU - Duster, Thomas A.
AU - Szymanowski, Jennifer E.S.
AU - Na, Chongzheng
AU - Fein, Jeremy B.
AU - Bunker, Bruce A.
N1 - Funding Information:
MRCAT is supported by the U.S. Department of Energy and the member institutions. Use of the APS was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. A.R.S. wishes to thank the staff at MRCAT, B. Mishra and K. Werellapatha for beamline support and useful conversations. Experiment used instrumentation at the Center for Environmental Science and Technology (CEST) at the University of Notre Dame. This research was supported, in part, by a fellowship to TAD from the Arthur J. Schmitt Foundation. The authors also wish to thank the two anonymous reviewers for their excellent comments.
PY - 2016
Y1 - 2016
N2 - Environmental toxic metal contamination remediation and prevention is an ongoing issue. Graphene oxide is highly sorptive for many heavy metals over a wide pH range under different ionic strength conditions. We present x-ray absorption fine structure (XAFS) spectroscopy results investigating the binding environment of Pb(II), Cd(II) and U(VI) ions onto multi-layered graphene oxide (MLGO). Analysis indicates that the dominant sorption mechanism of Pb to MLGO changes as a function of pH, with increasing inner sphere contribution as pH increases. In contrast, the sorption mechanism of Cd to MLGO remains constant under the studied pH range. This adsorption mechanism is an electrostatic attraction between the hydrated Cd+2 ion and the MLGO surface. The U(VI), present as the uranyl ion, changes only subtly as a function of pH and is bound to the surface via an inner sphere bond. Knowledge of the binding mechanism for each metal is necessary to help in optimizing environmental remediation or prevention in filtration systems.
AB - Environmental toxic metal contamination remediation and prevention is an ongoing issue. Graphene oxide is highly sorptive for many heavy metals over a wide pH range under different ionic strength conditions. We present x-ray absorption fine structure (XAFS) spectroscopy results investigating the binding environment of Pb(II), Cd(II) and U(VI) ions onto multi-layered graphene oxide (MLGO). Analysis indicates that the dominant sorption mechanism of Pb to MLGO changes as a function of pH, with increasing inner sphere contribution as pH increases. In contrast, the sorption mechanism of Cd to MLGO remains constant under the studied pH range. This adsorption mechanism is an electrostatic attraction between the hydrated Cd+2 ion and the MLGO surface. The U(VI), present as the uranyl ion, changes only subtly as a function of pH and is bound to the surface via an inner sphere bond. Knowledge of the binding mechanism for each metal is necessary to help in optimizing environmental remediation or prevention in filtration systems.
UR - http://www.scopus.com/inward/record.url?scp=84978776890&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/712/1/012094
DO - 10.1088/1742-6596/712/1/012094
M3 - Conference article
AN - SCOPUS:84978776890
VL - 712
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
SN - 1742-6588
IS - 1
M1 - 012094
Y2 - 23 August 2015 through 28 August 2015
ER -