Phase evolution of the surface iron (hydr)oxides to the iron sulfide through anion exchange during sulfidation of zero valent iron

Copyright © 2021 Elsevier B.V. All rights reserved..

The naturally-formed iron (hydr)oxides on the surface of zero valent iron (ZVI) have long been considered as passivation layer and inert phases which significantly reduce the reaction activities when they are employed in environmental remediation. Although it seems there are no direct benefits to keep these passivation layers, here, we show that such phases are necessary intermediates for the transformation to iron sulfides through an anion exchange pathway during sulfidation of ZVI. The pre-formed (hydr)oxides undergo a phase evolution upon aging and specific phases can be effectively trapped, which can be confirmed by a combination of different characterization techniques including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRPD), and X-ray absorption near edge structure (XANES) spectroscopy. Interestingly, after sulfidation, the resultant samples originated from different (hydr)oxides demonstrate different activities in the Cr(VI) sequestration. The XANES investigation of Fe K edge and Fe L2,3 edge indicates Fe remains the same after sulfidation, suggesting a non-redox, anion exchange reaction pathway for the production of iron sulfides, where O2- anions are directly replaced with S2-. Consequently, the structural characteristics of the parent (hydr)oxides are inherited by the as-formed iron sulfides, which make them behave differently because of their different structural natures.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:424

Enthalten in:

Journal of hazardous materials - 424(2022), Pt C vom: 15. Feb., Seite 127486

Sprache:

Englisch

Beteiligte Personen:

Li, Fengmin [VerfasserIn]
Zhang, Yue [VerfasserIn]
Tian, Boyang [VerfasserIn]
Zhou, Zheng [VerfasserIn]
Ye, Li [VerfasserIn]
Carozza, Jesse C [VerfasserIn]
Yan, Wensheng [VerfasserIn]
Han, Haixiang [VerfasserIn]
Xu, Chunhua [VerfasserIn]

Links:

Volltext

Themen:

Aging
Cr(VI) sequestration
E1UOL152H7
Ferrous Compounds
Ferrous sulfide
Iron
Iron (hydr)oxides
Journal Article
Oxides
Passivating layer
Research Support, Non-U.S. Gov't
TH5J4TUX6S
Water Pollutants, Chemical
XANES

Anmerkungen:

Date Completed 26.01.2022

Date Revised 26.01.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jhazmat.2021.127486

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM332742784