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Probing Facet-Dependent Iron Oxide Mineral Aggregation Behavior


EMSL Project ID
61059

Abstract

The goal of this project is to response to the review comments of paper “Facet-Dependent Dispersion and Aggregation of Aqueous Hematite Nanoparticles” submitted to Science Advances (Manuscript ID: adi7494). Previous EMSL-supported research (Proposals 51382) by our team led to a foundation of novel stabilization of nanoparticle suspension by facet-dependent dispersion. Facet engineering of nanocrystals offers an alternative approach to produce monodisperse suspensions simply based on facet-specific interaction with solvent molecules. We measure the dispersion/aggregation of three morphologies of hematite (α Fe2O3) nanoparticles in varied aqueous solutions using ex-situ electron microscopy and in-situ small angle X-ray scattering (SAXS). We demonstrate a unique tendency of (104) hematite nanoparticles to maintain a monodisperse state across a wide range of solution conditions not observed with (001)- and (116)-dominated particles. Density functional theory (DFT) calculations reveal an inert, densely hydrogen-bonded first water layer on the (104) facet that favors interparticle dispersion. The reviews have comments on the organic contamination and surface structure of synthesized hematite particles. We proposed to leverage the limited scope proposal to re-synthesize hematite nanoparticles with different facete-exposed and characterize the structure, morphology and organic contamination. This work was supported by EMSL user proposal 52382 previously and it was ended in Sep. 2022.

Project Details

Project type
Limited Scope
Start Date
2024-01-18
End Date
N/A
Status
Active

Team

Principal Investigator

Xin Zhang
Institution
Pacific Northwest National Laboratory