Chinese scientists have discovered a way to mass-produce nanosheets of transition metal tellurides, a 2D material they say could have many applications, from lithium batteries to solar panels.
The team, led by scientists from the Chinese Academy of Sciences and Peking University, said their “rapid and scalable” production method could take the nanosheets out of the lab and into practical use.
Writing in the peer-reviewed journal Nature last week, they said their method is faster and safer than existing ones, which have a much lower yield, and could be used to produce batteries with higher stability and energy density.
TMTs are a combination of the metal tellurium and transition metals such as tungsten and niobium. These can be made into 2D nanosheets, where the transition metal is “squeezed” by tellurium, CAS said in a statement.
It said TMT nanosheets are a promising area for development due to their unusual properties, including semiconducting and superconducting, insulating and magnetic activity.
The nanosheets could be used in areas ranging from energy storage and the development of “new electrodes” for supercapacitors and batteries to hydrogen production and photovoltaics, the statement said.
They can also be used as electrocatalysts to improve the performance of lithium-oxygen batteries because they are more stable and have a larger storage capacity, according to the paper.
“The list of industries that would benefit from significant efficiency improvements from the mass production of TMT nanosheets is extremely long,” Wu Zhongshuai, corresponding author and a chemist at CAS’s Dalian Institute of Chemical Physics, said in the statement.
“That’s why this 2D material is potentially so exciting.”
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But the potential of TMT nanosheets has not been explored as much as other 2D materials outside laboratories due to the lack of “safe, reproducible and scalable industrial-scale synthesis techniques,” the researchers wrote in the paper.
Nanosheets are typically produced by an “exfoliation” method, which uses chemical solutions to peel off thin layers of a compound to ultimately create extremely thin 2D sheets, according to CAS.
Previous production methods relied on toxic and flammable chemicals and could only create nanosheets at the gram level with long processing times of more than 30 minutes, limiting their applications, the paper said.
The team discovered a new method based on hydrolysis – the breaking of chemical bonds using water – which they found could produce more than 100 grams of nanosheets in less time.
“To our knowledge, our exfoliation method is the only one that allows production on such a large scale in just 10 minutes,” the team wrote.
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Their method starts with lithiation – where the hydrogen atoms in the molecules are replaced with lithium ones – followed by exfoliation done by hydrolysis.
They were able to produce 108 grams of niobium telluride nanosheets, two orders of magnitude more than previous methods. The team also used their method to create nanosheets using other transition metals, showing that the method is versatile, according to another CAS statement.
“We have developed a general solid-state lithiation and exfoliation method for the hundred-gram synthesis of high-quality TMT nanosheets, which has the potential to revolutionize their commercial production,” the team wrote in the paper.
They said their “universal and scalable” method could be used to explore “new quantum phenomena, potential applications and commercialization.”
