Authors: Youwei Zhang HuiLing Ma Jing Peng Maolin Zhai ZhongZhen Yu
Publish Date: 2012/10/20
Volume: 48, Issue: 5, Pages: 1883-1889
Abstract
Chemically reduced and functionalized graphene oxide GO was prepared by refluxing of GO with ethylenediamine ED using dimethyl formamide DMF as solvent It was confirmed that both ED and DMF contributed to the reduction and functionalization of GO The resulting adsorbent ED–DMF–RGO with amine groups was highly efficient in removing CrVI from its aqueous solution and could be easily separated by filtration The optimum pH for total Cr removal was observed at pH 20 and the CrVI removal capacity of ED–DMF–RGO at this pH was 9215 mg g−1 which was about 27 times higher than that of activated carbon even nearly 4–8 times higher than that of various modified activated carbons The presence of other ions such as Na+ K+ Ca2+ Cl− and Br− had little effect on the removal of CrVI Interestingly CrVI was reduced to lowtoxic CrIII during the adsorption process which followed an indirect reduction mechanism Both the CrVI adsorption and subsequent reduction of adsorbed CrVI to CrIII contributed to the CrVI removal The obtained ED–DMF–RGO may be applicable in CrVI removal if they are produced on a large scale and at low price in near future
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