'Nano-alloy' fabrication method has promise for new materials

It is claimed their discovery may change how the form and structure of nanomaterials are manipulated, particularly those used for gas storage, heterogeneous catalysis and lithium-ion batteries.

The findings are the subject of an article in the journal Small, co-authored by associate professor Mathew M. Maye and research assistant Wenjie Wu.

Until now, scientists have used many wet-chemical approaches to manipulate reactions in which metallic ions form alloys at the nanoscale. Here, metal nanoparticles are typically 2 to 50 nanometres in size and have unique properties, including high reactivity and novel chemistry.

‘At SU, we have developed a new synthetic pathway to tailor the internal microstructure of nanomaterials,’ Maye said in a statement.

Maye’s approach begins with a pre-synthesised iron nanoparticle core. After synthesising the core in its crystalline metallic form, he and Wu chemically deposit thin shells of chromium onto the iron.

When the core/shell nanoparticles are exposed to high temperatures, they anneal. Moreover, the iron and chromium diffuse into one another, forming an iron-chromium alloy shell thereby giving the core/alloy product an interface similar to some forms of stainless steel.