Novel core-shell sulfidated nano-Fe(0) particles for chromate sequestration: Promoted electron transfer and Fe(II) production

Xiaowei Zhu; Thao Thi Le; Jiangkun Du; Tiantian Xu; Yayun Cui; Haibo Ling; Sang Hoon Kim

doi:10.1016/j.chemosphere.2021.131379

Novel core-shell sulfidated nano-Fe(0) particles for chromate sequestration: Promoted electron transfer and Fe(II) production

Chemosphere. 2021 Dec:284:131379. doi: 10.1016/j.chemosphere.2021.131379. Epub 2021 Jun 29.

Authors

Xiaowei Zhu¹, Thao Thi Le², Jiangkun Du³, Tiantian Xu¹, Yayun Cui¹, Haibo Ling⁴, Sang Hoon Kim⁵

Affiliations

¹ School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China; Department of Environmental Science and Engineering, Hubei Water Systematic Pollution Control and Remediation Technology Center, China University of Geosciences, Wuhan, 430074, PR China.
² Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Division of Nano and Information Technology, KIST School, University of Science and Technology, Daejeon, 34113, Republic of Korea.
³ School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China; Department of Environmental Science and Engineering, Hubei Water Systematic Pollution Control and Remediation Technology Center, China University of Geosciences, Wuhan, 430074, PR China. Electronic address: djk929@hotmail.com.
⁴ School of Environmental Studies, China University of Geosciences, Wuhan, 430074, PR China; Hubei Academy of Environmental Sciences, Wuhan, 430072, PR China; Department of Environmental Science and Engineering, Hubei Water Systematic Pollution Control and Remediation Technology Center, China University of Geosciences, Wuhan, 430074, PR China.
⁵ Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea; Division of Nano and Information Technology, KIST School, University of Science and Technology, Daejeon, 34113, Republic of Korea. Electronic address: kim_sh@kist.re.kr.

PMID: 34225108
DOI: 10.1016/j.chemosphere.2021.131379

Abstract

Sulfidated nanoscale valent iron in form of FeS/Fe (0) shell-core nanoparticle has the aptitude to be a promising remediation material toward reductive removal of metal oxyanions. However, disrupted contact between Fe (0) core and FeS shell by thick iron oxides limited its reactivity improvement, and its mechanism of electron transfer remains unveiled. In this study, a novel sulfidated nZVI core-shell particles (FeS/Fe (0)) was fabricated via a modified post sulfidation approach to achieve a more uniform coverage of FeS for aqueous Cr(VI) sequestration. SEM and STEM tests confirmed the formation of the core-shell FeS/Fe (0) structure with a more solid interaction between FeS layer and Fe (0) core. The highest Cr(VI) removal rate was offered at optimal S/Fe molar ratio of 1/25 that the most chelated Fe²⁺ was also observed. The improved performance was due to that FeS shell with greater electronegativity could significantly accelerate the corrosion of Fe (0), facilitate the electron transfer form Fe (0) core to FeS shell according to the electrochemical tests. Moreover, FeS shell provided a protective layer for Fe (0) core so as to alleviate its anoxic passivation in water that FeS/Fe (0) had a better longevity for Cr(VI) removal than nFe (0). Characterizations of STEM and XPS revealed that Cr(VI) was reduced to Cr(III) and evenly coprecipitated with surface Fe(II)/Fe(III).

Keywords: Cr(VI); Electron transfer; Reduction; Sulfidation; Zero-valent iron.

MeSH terms

Chromates*
Chromium / analysis
Electrons
Ferric Compounds
Ferrous Compounds
Water Pollutants, Chemical* / analysis

Substances

Chromates
Ferric Compounds
Ferrous Compounds
Water Pollutants, Chemical
Chromium