Synthesis and characterization of redox-active ferric nontronite
[1];
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geochemistry Dept.
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Univ. of New Mexico, Albuquerque, NM (United States). Advanced Materials Lab.
- Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Civil Engineering
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nuclear Waste Disposal Research and Analysis
- Univ. of Connecticut, Storrs, CT (United States). Materials Science and Engineering
- Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
Heterogeneous redox reactions on clay mineral surfaces control mobility and bioavailability of redox-sensitive nutrients and contaminants. Iron (Fe) residing in clay mineral structures can either catalyze or directly participate in redox reactions; however, chemical controls over its reactivity are not fully understood. In our previous work we demonstrated that converting a minor portion of Fe(III) to Fe(II) (partial reduction) in the octahedral sheet of natural Fe-rich clay mineral nontronite (NAu-1) activates its surface, making it redox-active. In this study we produced and characterized synthetic ferric nontronite (SIP), highlighting structural and chemical similarities and differences between this synthetic nontronite and its natural counterpart NAu-1, and probed whether mineral surface is redox-active by reacting it with arsenic As(III) under oxic and anoxic conditions. We demonstrate that synthetic nontronite SIP undergoes the same activation as natural nontronite NAu-1 following the partial reduction treatment. Similar to NAu-1, SIP oxidized As(III) to As(V) under both oxic (catalytic pathway) and anoxic (direct oxidation) conditions. The similar reactivity trends observed for synthetic nontronite and its natural counterpart make SIP an appropriate analog for laboratory studies. The development of chemically pure analogs for ubiquitous soil minerals will allow for systematic research of the fundamental properties of these minerals.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Chemical Sciences, Geosciences, and Biosciences Division; USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Contributing Organization:
- https://www.osti.gov/elink/enhancement.do?action=load&ostiid=1402054
- Grant/Contract Number:
- AC05-76RL01830; AC02-06CH11357; NA-0003525; AC52-06NA25396; AC04-94AL85000
- OSTI ID:
- 1390580
- Alternate ID(s):
- OSTI ID: 1402054; OSTI ID: 1547089
- Report Number(s):
- PNNL-SA-124893; PII: S0009254117304084
- Journal Information:
- Chemical Geology, Vol. 470; ISSN 0009-2541
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
“Switching on” iron in clay minerals
|
journal | January 2019 |
Interfacial reactions of Cu(
|
journal | January 2020 |
Similar Records
Role of structural Fe in nontronite NAu-1 and dissolved Fe(II) in redox transformations of arsenic and antimony
Redox Transformations of As and Se at the Surfaces of Natural and Synthetic Ferric Nontronites: Role of Structural and Adsorbed Fe(II)