In-situ determination of non-classical mechanisms of crystallization during the abiotic reduction of Lepidocrocite via liquid cell TEM
EMSL Project ID
60642
Abstract
Lepidocrocite (LP) is commonly found in natural, anthropogenic mining environments and oxidized alloy steel waste containers. Despite its importance, the end products formed, its mineralization pathways including intermediate steps, and underlying mechanisms under Fe(II)(aq) catalysis remains unclear. To date, only snapshots via static analysis techniques (XRD, IR, Raman, XAS, ex-situ TEM, etc) have been employed to infer the end products that occur. Hence, there exists little to no information with respect to the intermediate products, particle attachment, or type of crystallization mechanisms (classical vs. non-classical) that occur along LP’s catalysis with Fe(II)(aq). Our preliminary data via semi in-situ TEM has shown us that two novel non-classical mechanisms of crystallization (NCMC) appear to occur. The first results in the formation of circular geometry core-shell nanoparticles possibly through some guided orientation mechanism. While the second is reminiscent of a bacterial-like particle attachment, disintegration, and re-arrangement through a thin film possibly guided by “inorganic sensor” like nano-wire antennas and nano-wires. However, due to the fact, only snap-shots were obtained, questions remain such as (1) are the core-shell nano-particles really formed through some guided type of oriented mechanism? (2) do these nano-wire antennas and wires really have some “inorganic sensory-like” function during particle attachment? (3) could the electron transparent film media behave as a quasi-liquid interface? Therefore, based on this gap of information, we plan to conduct real-time Liquid Cell TEM at the experimental conditions where the snap-shots of the NCMC’s were observed to obtain more temporal and structural information to solidify our findings. The results obtained from this work will enable us and the community to (i) establish more accurate phase transformation conceptual models of this reaction, (ii) understand how we can create and manipulate particular nano-geometries of a material commonly found in environmental and energy applications and (iii) understand how some inorganic nano-particles may have certain sensory-like functionality under abiotic redox conditions.
Project Details
Project type
Limited Scope
Start Date
2023-05-25
End Date
2023-11-10
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members