Improvement of zinc substitution in the reactivity of magnetite coupled with aqueous Fe(II) towards nitrobenzene reduction

Ying Li, Gaoling Wei, Hongping He, Xiaoliang Liang, Wei Chu, Deyin Huang, Jianxi Zhu, Wei Tan, Qiuxin Huang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)

Abstract

The reduction of nitrobenzene (NB) by Zn-substituted magnetite coupled with aqueous Fe(II) was studied. A series of Zn-substituted magnetites (Fe3−xZnxO4, x = 0, 0.25, 0.49, 0.74, and 0.99) were synthesized by a coprecipitation method followed by systematic analysis of the variation in structure and physicochemical properties of magnetite using XRD, TEM, TG, BET and XAFS. All of the samples had a spinel structure by Zn substitution. Zn2+primarily occupied the tetrahedral sites, but a portion of them moved to the octahedral sites at higher Zn level. Zn substitution increased the BET specific surface area and surface hydroxyl amount. The electron balance indicated that the NB reduction was primarily through the heterogeneous reaction by Fe3−xZnxO4and adsorbed Fe(II), where NB in aqueous solution was reduced by structural Fe2+in magnetite recharged by adsorbed Fe(II). Various factors, such as aqueous Fe(II) concentration, magnetite stoichiometry and Zn level, were investigated to illustrate their effects on the reduction processes. Both the rate constant kobsand electron transfer amount illustrated that Zn substitution generally improved the reduction activity of the Fe3−xZnxO4/Fe(II) system, while overdose of Zn retarded the process. This issue was attributed to the variation in electron conductivity of Fe3−xZnxO4and Zn2+occupancy.
Original languageEnglish
Pages (from-to)104-112
Number of pages9
JournalJournal of Colloid and Interface Science
Volume517
DOIs
Publication statusPublished - 1 May 2018

Keywords

  • Aqueous Fe(II)
  • Electron transfer
  • Nitrobenzene
  • Reduction
  • Zn-substituted magnetite

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

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