Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

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)
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)

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials

Houston, TX | Posted on April 18th, 2018

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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the paper at:

Yakobson Research Group:

Department of Materials Science and NanoEngineering:

Related News Press

Videos/Movies

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

DNA origami to scale-up molecular motors June 13th, 2019

News and information

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Small currents for big gains in spintronics: A new low-power magnetic switching component could aid spintronic devices June 14th, 2019

2 Dimensional Materials

Kanazawa University research: Opposite piezoresistant effects of rhenium disulfide in two principle directions June 13th, 2019

2D crystals conforming to 3D curves create strain for engineering quantum devices June 7th, 2019

UCI scientists create new class of two-dimensional materials: Fabrication could help unlock new quantum computing and energy technologies June 6th, 2019

Chemistry

Neutrons unlock the secrets of limoncello May 21st, 2019

Army discovery opens path to safer batteries May 10th, 2019

Coal could yield treatment for traumatic injuries: Rice, Texas A&M, UTHealth scientists discover coal-derived ‘dots’ are effective antioxidant April 25th, 2019

Hardware

New way to beat the heat in electronics: Rice University lab's flexible insulator offers high strength and superior thermal conduction May 16th, 2019

CEA-Leti Develops CMOS Process for High-Performance MicroLEDs That Could Overcome Display-Size Obstacles: New Concept Creates All-in-One RGB MicroLEDs, Eliminates Several Transfer Steps to Receiving Substrate & Boosts Performance May 16th, 2019

Govt.-Legislation/Regulation/Funding/Policy

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Mysterious Majorana quasiparticle is now closer to being controlled for quantum computing: Princeton researchers detect a robust Majorana quasiparticle and show how it can be turned on and off June 14th, 2019

Possible Futures

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Mysterious Majorana quasiparticle is now closer to being controlled for quantum computing: Princeton researchers detect a robust Majorana quasiparticle and show how it can be turned on and off June 14th, 2019

University of Konstanz researchers create uniform-shape polymer nanocrystals: Researchers from the University of Konstanz's CRC 1214 'Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures' generate uniform-shape nanocrystals using direct polymeriz June 14th, 2019

Chip Technology

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Mysterious Majorana quasiparticle is now closer to being controlled for quantum computing: Princeton researchers detect a robust Majorana quasiparticle and show how it can be turned on and off June 14th, 2019

Small currents for big gains in spintronics: A new low-power magnetic switching component could aid spintronic devices June 14th, 2019

Sensors

New Video Highlights Specific Topics Sought in Call for Papers for the 2019 IEEE International Electron Devices Meeting (IEDM) June 13th, 2019

Kanazawa University research: Opposite piezoresistant effects of rhenium disulfide in two principle directions June 13th, 2019

Shaking hands with human or robot? Nanotubes make them alike as never before June 6th, 2019

Good vibrations: Using piezoelectricity to ensure hydrogen sensor sensitivity May 24th, 2019

Discoveries

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

University of Konstanz researchers create uniform-shape polymer nanocrystals: Researchers from the University of Konstanz's CRC 1214 'Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures' generate uniform-shape nanocrystals using direct polymeriz June 14th, 2019

Materials/Metamaterials

University of Konstanz researchers create uniform-shape polymer nanocrystals: Researchers from the University of Konstanz's CRC 1214 'Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures' generate uniform-shape nanocrystals using direct polymeriz June 14th, 2019

Laser technique could unlock use of tough material for next-generation electronics: Researchers make graphene tunable, opening up its band gap to a record 2.1 electronvolts May 30th, 2019

Building next gen smart materials with the power of sound May 28th, 2019

ZEN gets $1m grant for graphene-enhanced concrete project May 12th, 2019

Announcements

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Small currents for big gains in spintronics: A new low-power magnetic switching component could aid spintronic devices June 14th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

New record: 3D-printed optical-electronic integration June 18th, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

University of Konstanz researchers create uniform-shape polymer nanocrystals: Researchers from the University of Konstanz's CRC 1214 'Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures' generate uniform-shape nanocrystals using direct polymeriz June 14th, 2019

Research partnerships

2D crystals conforming to 3D curves create strain for engineering quantum devices June 7th, 2019

Shaking hands with human or robot? Nanotubes make them alike as never before June 6th, 2019

Beyond 1 and 0: Engineers boost potential for creating successor to shrinking transistors May 30th, 2019

Laser technique could unlock use of tough material for next-generation electronics: Researchers make graphene tunable, opening up its band gap to a record 2.1 electronvolts May 30th, 2019

Solar/Photovoltaic

'Hot spots' increase efficiency of solar desalination: Rice University engineers boost output of solar desalination system by 50% June 19th, 2019

UCI scientists create new class of two-dimensional materials: Fabrication could help unlock new quantum computing and energy technologies June 6th, 2019

Data science helps engineers discover new materials for solar cells and LEDs May 24th, 2019

Quantum rebar: Quantum dots enhance stability of solar-harvesting perovskite crystals: Researchers demonstrate that perovskite crystals and quantum dots working together can increase stability of solar materials May 24th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project