26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Mimicking Lightning to turn Minerals into Nanomaterials

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral AIP | Condensed Matter & Materials (CMM)

Speaker

Mr Chenkai Jiang (School of Chemistry, The University of Sydeny)

Description

Lightning has long been considered a powerful energy source for prebiotic chemistry on the early Earth. Recent studies show that lightning-induced plasma electrochemistry can activate inert starting materials, such as a prebiotic atmosphere, water, and rocks, into more reactive chemical feedstocks relevant to the origin of life.\textsuperscript{1} Inspired by this scenario, we explore the ability of lightning-like spark discharge to transform abundant sedimentary minerals into structurally modified nanoparticles that may have acted as catalysts or reactive surfaces for prebiotic synthesis.

Here, carbonate mineral slurries, including $\mathrm{MgCO_3}$, $\mathrm{FeCO_3}$, $\mathrm{ZnCO_3}$, and $\mathrm{MnCO_3}$, containing different $\mathrm{NaCl}$ concentrations were treated using high-voltage spark discharge at air--liquid--solid interfaces. The resulting changes in particle structure were examined using dynamic light scattering (DLS), UV--Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Plasma-induced radical electrochemistry can change the hydrodynamic particle size distribution; many samples showed a particle-size reduction of more than $50\%$, and in some cases the particle diameter decreased to below $100~\mathrm{nm}$. This process is strongly influenced by salinity levels. These results suggest that localized heating, reactive radical species, interfacial reactions, and ionic strength collectively influence mineral particle restructuring processes.

This work establishes plasma electrochemistry as a platform for turning naturally abundant carbonate minerals into functional nanomaterials under mild slurry-phase conditions. Beyond its relevance to early-Earth mineral activation and the chemical origin of life, this approach also points toward new sustainable strategies for electrified production of functional materials from abundant geological resources, such as air, water, and rocks, without relying on conventional high-temperature or resource-intensive synthetic routes.

Reference
(1) Jiang, H. J.; Underwood, T. C.; Bell, J. G.; Whitesides, G. M.; et al. Mimicking Lightning-Induced Electrochemistry on the Early Earth. Proc. Natl. Acad. Sci. 2024, 121 (32), e2400819121.