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Updated: Jan 24, 2026

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM
Published on: September 27, 2017
In situ observations of gold deposition in a dense liquid layer at the pyrite-water interface
Hongmei Tang1, Haiyang Xian2,3,4,5, Teng Deng6
1Jiangxi Provincial Key Laboratory of Greenhouse Gas Accounting and Carbon Reduction, Institute of Energy Research, Jiangxi Academy of Sciences, Nanchang 330096, China.
Abstract:
Pyrite-triggered precipitation of gold nanoparticles (AuNPs) is crucial for generating high-grade gold deposits, yet its dynamic process and mechanism at the pyrite-water interface remain unclear due to the lack of in situ observation. Here, utilizing in situ liquid cell transmission electron microscopy, we find a dense liquid layer mediated deposition of AuNPs at the pyrite-water interface in parts per billion-level gold-bearing solutions, a concentration that resembles crustal abundances. Real-time imaging reveals that a dense liquid layer forms at the pyrite-water interface, and it is proposed that AuNPs nucleate and grow in this layer. Results from in situ atomic force microscopy and ex situ transmission electron microscopy indicate that the growth kinetic process of AuNPs involves monomer-to-cluster aggregation, further enriching gold at the pyrite-water interface. Thermodynamic modeling demonstrates that precipitation of AuNPs is primarily driven by the oxygen fugacity decrease in the dense liquid layer due to pyrite dissolution. These findings reveal a localized gold concentration mechanism to interpret adsorption and nucleation of AuNPs on pyrite during its dissolution-precipitation cycles, which significantly enhances our understanding of the highly effective gold scavenging from fluid by pyrite. The mechanism of nanoparticle formation in the dense liquid layer at dissolving mineral-fluid interfaces represents a fundamental process that could be common in nature.
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