Researchers create nanostructured 2D gold monolayers

Researchers at Lund University and Hokkaido University have achieved a significant advancement in nanomaterial engineering by creating nearly freestanding nanostructured two-dimensional (2D) gold monolayers. This development has the potential to transform various fields, including catalysis, electronics, and energy conversion.

Gold is a noble metal that forms solid three-dimensional (3D) structures, can exhibit extraordinary properties when in its 2D form, such as unique electronic behaviors and increased surface reactivity, which could lead to groundbreaking applications in catalysis and advanced electronic devices.

One of the primary challenges in producing 2D gold monolayers is stabilizing isotropic metallic bonds. To overcome this problem, the research team utilized a novel bottom-up approach complemented by high-performance computations.

This innovative method allowed them to produce macroscopically large gold monolayers characterized by unique nanostructured patterns, high thermal stability, and promising catalytic capabilities.

The team successfully grew these gold monolayers on an iridium substrate and strategically embedded boron atoms at the interface between the gold and iridium layers. This creative technique resulted in suspended monoatomic sheets of gold with a hexagonal configuration and nanoscale triangular patterns. The incorporation of boron significantly enhanced both the stability and structural integrity of the gold layers, enabling the formation of the nanostructures.

“The ease of preparation and thermal stability of the resulting gold films is significant, making them a practical platform for further studies of fundamental properties of elemental 2D metals and their potential for diverse applications in electronics and nanotechnology,” explains Dr. Alexei Preobrajenski of the MAX IV Laboratory, Lund University, and a corresponding author of the study.

Cutting-edge characterization techniques such as scanning tunneling microscopy (STM) and X-ray spectroscopy have been utilized to explore the structural and electronic properties of gold films in depth. Their findings reveal that the incorporation of boron initiates a remarkable transition from three-dimensional to predominantly two-dimensional metal bonding, significantly changing the electronic properties of the gold layers.

The unique properties of these synthesized films stand out, as conventional methods often struggle to produce a stable 2D metallic form, resulting in small or unstable structures. The potential to engineer stable and nearly freestanding metallic monolayers across expansive areas opens exciting avenues for innovation.

“This research opens avenues for testing theories and further exploration into the potential applications of 2D metals in the various fields, including catalysis and energy conversion,” says Associate Professor Andrey Lyalin of the Faculty of Science, Hokkaido University, and the other corresponding author of the study.

This research aids in enhancing the comprehension of 2D materials by tackling the difficulties associated with stabilizing 2D metallic substances and establishes a foundation for possible technological uses.

Journal reference:

1. Alexei Preobrajenski, Nikolay Vinogradov, David A. Duncan, Tien-Lin Lee, Mikhail Tsitsvero, Tetsuya Taketsugu & Andrey Lyalin. Boron-induced transformation of ultrathin Au films into two-dimensional metallic nanostructures. Nature Communications, 2024; DOI: 10.1038/s41467-024-54464-y