Linköping University Researchers Pioneer the Synthesis of 'Goldene - a Monolayer Gold Material

Researchers form Linköping University, Sweden, publish a novel method for synthesizing "goldene," a monolayer of gold, achieved by etching away Ti3C2 from a nanolaminated Ti3AuC2 structure using a hydrofluoric acid-free process. The Ti3AuC2 was initially formed by substituting Si in Ti3SiC2 with Au, utilizing a unique aspect of MAX phases—materials characterized by their layered structures and the ability to etch away specific layers. This process not only highlights a new avenue in the synthesis of 2D materials but also overcomes the limitations of previous methods that often required more complex and less environmentally friendly chemicals. The resulting goldene exhibits a lattice contraction of about 9% compared to bulk gold, confirmed via electron microscopy, with further characterization showing an increase in the Au 4f binding energy by 0.88 eV, suggesting altered electronic properties.

Graphical abstract. (From: Synthesis of goldene comprising single-atom layer gold)

The practical implications of goldene extend to various advanced technological applications. Its high surface-area-to-volume ratio, a characteristic of two-dimensional materials, could significantly enhance its catalytic and electronic properties. Applications in fields such as electronics, catalysis, and medicine are discussed, with potential uses ranging from improved catalytic converters to novel approaches in cancer treatment through photothermal therapies. The intrinsic stability of goldene, supported by ab initio molecular dynamics simulations, suggests that despite some physical challenges like curling and agglomeration, the material holds substantial promise for the development of next-generation devices and systems.

The production of atomically thin gold layers in the past typically involved methods that produce few atoms in thickness rather than true monolayers and often required complex supporting substrates or matrices to stabilize the gold layer. The method of exfoliating gold from a nanolaminated MAX phase as described in the publication is a novel approach, potentially opening new pathways for the production and application of gold in nanotechnology and materials science.

 

Schematic illustration of the preparation of goldene. (From: Synthesis of goldene comprising single-atom layer gold),

The production process of goldene is scalable and could potentially be adapted for the synthesis of other non-van der Waals 2D materials. The study outlines further research avenues, including the exploration of different etching schemes and surfactants to enhance the stability and yield of the synthesized layers. The success in manipulating the atomic structure of gold at such a fundamental level not only paves the way for innovative applications but also deepens our understanding of material science at the atomic scale, opening doors to new research in 2D material science.

Source: Synthesis of goldene comprising single-atom layer gold | Nature Synthesis