• 文献标题:   Nanoscale Zero-Valent Iron (nZVI) assembled on magnetic Fe3O4/graphene for Chromium (VI) removal from aqueous solution
  • 文献类型:   Article
  • 作  者:   LV XS, XUE XQ, JIANG GM, WU DL, SHENG TT, ZHOU HY, XU XH
  • 作者关键词:   nanoscale zerovalent iron, magnetic graphene, cr vi removal, synergistic effect
  • 出版物名称:   JOURNAL OF COLLOID INTERFACE SCIENCE
  • ISSN:   0021-9797 EI 1095-7103
  • 通讯作者地址:   Zhejiang Univ
  • 被引频次:   89
  • DOI:   10.1016/j.jcis.2013.11.044
  • 出版年:   2014

▎ 摘  要

Nanoscale Zero-Valent Iron (nZVI) assembled on magnetic Fe3O4/graphene (nZVI@MG) nanocomposites was synthesized for Cr(VI) removal from aqueous solution. nZVI particles were perfectly dispersed either among Fe3O4 nanoparticles (Fe3O4 NPs) or above the basal plane of graphene. This material shows Cr(VI) removal efficiency of 83.8%, much higher than those of individuals (18.0% for nZVI, 21.6% for Fe3O4 NPs and 23.7% for graphene) and even their sum of 63.3%. The removal process obeys pseudo-second-order adsorption model, suggesting that adsorption is rate-controlling step. Maximum Cr(VI) adsorption capacity varies from 66.2 to 101.0 mg g(-1) with decreasing pH from 8.0 to 3.0 at 30 degrees C. Negative Delta G and Delta H indicate spontaneous tendency and exothermic nature. Robust performance of nZVI@MG arises from the formation of micro-nZVI-graphene/nZVI-Fe3O4 batteries and strong adsorption capability of broad graphene sheet/Fe3O4 surfaces. Electrons released by nZVI spread all over the surfaces of graphene and Fe3O4, and the adsorbed Cr(VI) ions on them capture these floating electrons and reduce to Cr(III). Fe3O4 NPs also served as protection shell to prevent nZVI from agglomeration and passivation. (C) 2013 Elsevier Inc. All rights reserved.