Showing posts with label gold. Show all posts
Showing posts with label gold. Show all posts

Monday, April 22, 2024

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

Tuesday, February 23, 2021

Thermal Atomic Layer Deposition of Gold: Mechanistic Insights, Nucleation, and Epitaxy

Here is a new paper with deep insights into thermal ALD of gold from Argonne National Lab in the USA. They are using the previously developed precursor from Mikko Titalas ALD group at Helsinki University Finland Me2Au(S2CNEt2). All depositions were carried out in a Veeco CNT Savannah reactor.

Thermal Atomic Layer Deposition of Gold: Mechanistic Insights, Nucleation, and Epitaxy

Pengfei Liu, Yuchen Zhang, Cong Liu, Jonathan D. Emery, Anusheela Das, Michael J. Bedzyk,
Adam S. Hock*, and Alex B. F. Martinson*
ACS Appl. Mater. Interfaces 2021, XXXX, XXX, XXX-XXX
Publication Date:February 9, 2021https://doi.org/10.1021/acsami.0c17943

An in situ microbalance and infrared spectroscopic study of alternating exposures to Me2Au(S2CNEt2) and ozone illuminates the organometallic chemistry that allows for the thermal atomic layer deposition (ALD) of gold. In situ quartz crystal microbalance (QCM) studies resolve the nucleation delay and island growth of Au on a freshly prepared aluminum oxide surface with single cycle resolution, revealing inhibition for 40 cycles prior to slow nucleation and film coalescence that extends over 300 cycles. In situ infrared spectroscopy informed by first-principles computation provides insight into the surface chemistry of the self-limiting half-reactions, which are consistent with an oxidized Au surface mechanism. X-ray diffraction of ALD-grown gold on silicon, silica, sapphire, and mica reveals consistent out-of-plane oriented crystalline film growth as well as epitaxially directed in-plane orientation on closely lattice-matched mica at a relatively low growth temperature of 180 °C. A more complete understanding of ALD gold nucleation, surface chemistry, and epitaxy will inform the next generation of low-temperature, nanoscale, textured depositions that are applicable to high surface area supports.



Thursday, April 9, 2015

Gooooooold! #ALDep #BarryLab in Canada

Twitter 6th of April 2015:

"Gooooooold! #ALDep #BarryLab"
"It is hard to express how beautiful this UNIFORM GOLD FILM actually looks... #ALDep "

We all must agree it does look beautiful and we can´t wait to get more details on this ALD Process from Sean Barry & Co at Barry LabDepartment of Chemistry Carleton University in Canada


Uniform gold deposited by ALD in Barry Lab (picture from twitter)


Team Canada - gold medalists (from left) Goran Bacic, Peter Gordon, Agnes Kurek, Prof. Awesome, Sydney Buttera, Jackie Addo, Jenny Mcleod, Matt Griffiths, Peter Pallister, Dave Madia. (from Barry Lab Web page)

http://www.hankstruckpictures.com/pix/trucks/fgruin/scandinavian_trucks/fg_scand_4c.jpg 

I think this one is heading to Canada and that Juhana Kostamo is the driver, there is a reflection so it is hard to judge but it could also be Timo Malinen who´s driving with Juhana as co-driver.

 
Canadian Bow Tie


Some bald guy