School of Engineering News
Warwick Researchers Help Reveal How Table Salt “Switches On” Gold at the Nanoscale
A groundbreaking collaboration has revealed how a humble ingredient, table salt, can dramatically transform the chemistry of gold at the nanoscale. Led by the Cavendish Laboratory at Cambridge, the research draws deeply on theoretical modelling from the University of Warwick, bringing fresh insight to gold’s behaviour in nanotechnology applications.
The study, published in Nature Chemistry, shows that minute amounts of chloride (from salt) can rearrange the surface of gold by forming a thin, transient gold–chloride (Au–Cl) layer. This “switchable” layer stabilises the gold in certain conditions, then reorganises in response to environmental changes.
At Warwick, Professor Hatef Sadeghi and his team deployed advanced computational techniques to uncover how the Au–Cl adlayer emerges through subtle changes in charge distribution. Their models explain how this layer acts as a dynamic stabiliser, helping to reset gold surfaces, potentially making them more reproducible, durable, and easier to regenerate.
This insight has real-world implications: gold nanoparticles are central to devices such as sensors, diagnostic tools, and catalysts. But until now, controlling how molecules bind to gold surfaces has been a major barrier to consistent performance. The discovery of the Au–Cl layer opens up avenues to engineer gold-based materials that are more robust, reusable and stable.
Looking ahead, the researchers aim to extend this mechanism beyond gold, to other precious metals such as platinum and palladium, potentially revolutionising how we design nanomaterials for clean energy, diagnostics, and sensing.
Reflecting on the work, Professor Sadeghi commented:
“It is remarkable how small changes in the charge redistribution on the gold surface led to such large changes in its properties,” said Professor Hatef Sadeghi, who led the work at Warwick.
This project was supported by the Engineering and Physical Sciences Research Council (EPSRC) under its Ubiquitous Optical Healthcare Technologies (UbOHT) programme, with experimental data provided by Diamond Light Source.