Research team explores the potential of MXenes in nanotechnology applications
Materials scientists at the University of Nebraska-Lincoln are studying the physical properties of MXenes. MXenes are a rapidly growing family of two-dimensional materials with potential for many nanotechnology applications.
The team’s research builds on nearly 20 years of research into graphene. Graphene is another family of 2D materials that has important applications in many fields, but it has some drawbacks when compared to MXene (pronounced “maxen”). The team’s latest research is published in the journal Matter.
MXenes are made of atomically thin layers of transition metal carbides, nitrides, or carbonitrides. They begin with what is called the MAX phase, the name describing its characteristic component. “M” is a transition metal such as titanium or chromium. “A” elements such as aluminum. “X” represents a carbon or nitrogen atom. Components are packed into a hierarchical structure. To synthesize MXene, chemists used an acidic solution to etch a layer of the “A” element, leaving the other layers alone. This is a relatively simple and high-yielding technique.
Dozens of MXenes with different combinations of “M” and “X” elements have been synthesized. The Nebraska research team focused on a little-studied version that contains chromium, titanium and carbon atoms, said Alexander Sinitsky, a chemistry professor and lead researcher.
“This field is growing rapidly,” Sinitsky said.
MXene has proven useful for energy storage, water purification, protection from electromagnetic interference, and biomedical applications.
The key to its usefulness is its chemical and structural diversity, as well as its scalability and processability, said Sinitzky, who is also with the Nebraska Center for Materials and Nanoscience.
MXene has a large surface area and is easily adjustable. It is also highly responsive to light and its surface is terminated with oxygen and hydroxyl, making it hydrophilic (attracted to water).
Sinitsky’s team found that MXene, which contains chromium and titanium, has “a set of properties not found in anything else.” Previous research by the Nebraska team on other MXene materials revealed their n-type (electron-rich) properties and decreased conductivity in response to light. In contrast, this new material is the first MXene to demonstrate p-type (electron-deficient) properties and increased conductivity under illumination.
“These are very unusual characteristics for MXenes,” Sinitsky said. “Many electronic applications require both n-type and p-type materials, and they are used in combination. All of the previously studied MXenes were n-type, but now we have developed the first p-type material. We have demonstrated that type MXenes should enable complex structures in which complementary MXenes can be used together to achieve new electronic functions. ”
His team was also able to produce flakes of chromium/titanium carbide MXene that are larger and more uniform than previously available, making them easier to study and use.
Other authors are Saman Bagheri, a postdoctoral fellow in chemistry; Michael J. Loes, graduate student, chemistry. Haidong Lu, Research Assistant Professor, Physics and Astronomy. Rashmeet Khurana, graduate student, chemistry. Md. Ibrahim Kholil, Graduate Student, Chemistry. and Alexei Gruberman, Mach Professor of Physics and Astronomy. Co-authors are Alexei Lipatov, Kimananda Acharya, and Tula R. Paudel, all from the South Dakota School of Mines and Technology.
Further information: Saman Bagheri et al. Synthesis of high-quality large Cr2TiC2T MXene monolayers, their mechanical properties, p-type electrical transport, and positive photoresponse, Matter (2024). DOI: 10.1016/j.matt.2024.08.019
Provided by University of Nebraska-Lincoln
Source: Research team explores potential of MXenes for nanotech applications (October 28, 2024) from https://phys.org/news/2024-10-team-explores-potential-mxenes-nanotech.html Retrieved October 28, 2024
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