Home > Press > Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials
![]() |
Rice University scientists built computer models of intermediate reactions to understand why salt lowers reaction temperatures in the synthesis of two-dimensional compounds. Above left, molybdenum oxychloride precursor molecules undergo sulfurization in which sulfur atoms replace oxygen atoms. That sets up the material to form new compounds. At right, the calculations show the charge densities of the new molecules. (Credit: Yakobson Group/Rice University) |
Abstract:
A dash of salt can simplify the creation of two-dimensional materials, and thanks to Rice University scientists, the reason is becoming clear.
A molecular dynamics simulation by Rice University scientists shows a layer of salt and molybdenum oxide mixing together to form molybdenum oxychloride. The atoms are oxygen (red), sodium (yellow), chlorine (green) and molybdenum (purple). (Credit: Yakobson Group/Rice University)
Boris Yakobson, a Rice professor of materials science and nanoengineering and of chemistry, was the go-to expert when a group of labs in Singapore, China, Japan and Taiwan used salt to make a "library" of 2-D materials that combined transition metals and chalcogens.
These compounds could lead to smaller and faster transistors, photovoltaics, sensors and catalysts, according to the researchers.
Through first-principle molecular dynamics simulations and accurate energy computations, Yakobson and his colleagues determined that salt reduces the temperature at which some elements interact in a chemical vapor deposition (CVD) furnace. That makes it easier to form atom-thick layers similar to graphene but with the potential to customize their chemical composition for specific layer-material and accordingly electrical, optical, catalytic and other useful properties.
The research team including Yakobson and Rice postdoctoral researcher Yu Xie and graduate student Jincheng Lei reported its results this week in Nature.
The team led by Zheng Liu of Nanyang Technological University in Singapore used its seasoned technique with CVD to create 47 compounds of metal chalcogenides (which contain a chalcogen and an electropositive metal). Most of the new compounds had two ingredients, but some were alloys of three, four and even five. Many of the materials had been imagined and even coveted, Yakobson said, but never made.
In the CVD process, atoms excited by temperatures -- in this case between 600 and 850 degrees Celsius (1,112 and 1,562 degrees Fahrenheit) -- form a gas and ultimately settle on a substrate, linking to atoms of complementary chemistry to form monolayer crystals.
Researchers already suspected salt could facilitate the process, Yakobson said. Liu came to him to request a molecular model analysis to learn why salt made it easier to melt metals with chalcogens and get them to react. That would help them learn if it might work within the broader palette of the periodic table.
"They did impressively broad work to make a lot of new materials and to characterize each of them comprehensively," Yakobson said. "From our theoretical perspective, the novelty in this study is that we now have a better understanding of why adding plain salt lowers the melting point for these metal-oxides and especially reduces the energy barriers of the intermediates on the way to transforming them into chalcogenides."
Whether in the form of common table salt (sodium chloride) or more exotic compounds like potassium iodide, salt was found to allow chemical reactions by lowering the energetic barrier that otherwise prevents molecules from interacting at anything less than ultrahigh temperatures, Yakobson said.
"I call it a 'salt assault,'" he said. "This is important for synthesis. First, when you try to combine solid particles, no matter how small they are, they still have limited contact with each other. But if you melt them, with salt's help, you get a lot of contact on the molecular level.
"Second, salt reduces the sublimation point, where a solid undergoes a phase transformation to gas. It means more of the material's component molecules jump into the gas phase. That's good for general transport and contact issues and helps the reaction overall."
The Rice team discovered the process doesn't facilitate the formation of the 2-D-material itself directly so much as it allows for the formation of intermediate oxychlorides. These oxychlorides then lead to the 2-D chalcogenide growth.
Detailing this process required intensive atom-by-atom simulations, Yakobson said. These took weeks of heavy-duty computations of the quantum interactions among as few as about 100 atoms – all to show just 10 picoseconds of a reaction. "We only did four of the compounds because they were so computationally expensive, and the emerging picture was clear enough," Yakobson said.
Co-authors of the paper are Jiadong Zhou, Fucai Liu, Qundong Fu, Qingsheng Zeng, Hong Wang, Yu Chen, Juan Xia, Ting Yu and Zexiang Shen of Nanyang Technological University, Singapore; Junhao Lin and Kazu Suenaga of the National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan; Xiangwei Huang, Guangtong Liu, Yao Zhou and Qian Liu of the Chinese Academy of Sciences, Beijing; Huimei Yu of East China University of Science and Technology, Shanghai; Di Wu and Chuang-Han Hsu of the National University of Singapore; Changli Yang and Li Lu of the Chinese Academy of Sciences and Collaborative Innovation Center of Quantum Matter, Beijing; and Hsin Lin of the National University of Singapore and the Institute of Physics, Academia Sinica, Taipei, Taiwan.
The U.S. Department of Energy, Singapore National Research Foundation, JST-ACCEL, JSPS KAKENHI, the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Ministry of Science and Technology of China and the Chinese Academy of Sciences supported the research.
####
About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,970 undergraduates and 2,934 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for quality of life and for lots of race/class interaction and No. 2 for happiest students by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance. To read “What they’re saying about Rice,” go to http://tinyurl.com/RiceUniversityoverview .
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,970 undergraduates and 2,934 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for quality of life and for lots of race/class interaction and No. 2 for happiest students by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance. To read “What they’re saying about Rice,” go to http://tinyurl.com/RiceUniversityoverview.
For more information, please click here
Contacts:
David Ruth
713-348-6327
Mike Williams
713-348-6728
Copyright © Rice University
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Department of Materials Science and NanoEngineering:
Related News Press |
Chemistry
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Chainmail-like material could be the future of armor: First 2D mechanically interlocked polymer exhibits exceptional flexibility and strength January 17th, 2025
News and information
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
2 Dimensional Materials
Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025
New 2D multifractal tools delve into Pollock's expressionism January 17th, 2025
Chainmail-like material could be the future of armor: First 2D mechanically interlocked polymer exhibits exceptional flexibility and strength January 17th, 2025
Hardware
The present and future of computing get a boost from new research July 21st, 2023
Videos/Movies
New X-ray imaging technique to study the transient phases of quantum materials December 29th, 2022
Solvent study solves solar cell durability puzzle: Rice-led project could make perovskite cells ready for prime time September 23rd, 2022
Scientists prepare for the world’s smallest race: Nanocar Race II March 18th, 2022
Visualizing the invisible: New fluorescent DNA label reveals nanoscopic cancer features March 4th, 2022
Govt.-Legislation/Regulation/Funding/Policy
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025
Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025
Possible Futures
Ben-Gurion University of the Negev researchers several steps closer to harnessing patient's own T-cells to fight off cancer June 6th, 2025
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Chip Technology
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Programmable electron-induced color router array May 14th, 2025
Enhancing power factor of p- and n-type single-walled carbon nanotubes April 25th, 2025
Ultrafast plasmon-enhanced magnetic bit switching at the nanoscale April 25th, 2025
Sensors
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
Nanotechnology: Flexible biosensors with modular design November 8th, 2024
Discoveries
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Materials/Metamaterials/Magnetoresistance
Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025
Announcements
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025
Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025
Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025
A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025
Research partnerships
HKU physicists uncover hidden order in the quantum world through deconfined quantum critical points April 25th, 2025
SMART researchers pioneer first-of-its-kind nanosensor for real-time iron detection in plants February 28th, 2025
Solar/Photovoltaic
KAIST researchers introduce new and improved, next-generation perovskite solar cell November 8th, 2024
Groundbreaking precision in single-molecule optoelectronics August 16th, 2024
Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024
Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |