A collaborative team of researchers from Drexel University, the Chinese Academy of Sciences, and Linköping University has introduced a groundbreaking method for atomically tailoring layered nanomaterials. The approach, described in *Science*, enables scientists to cut apart and reassemble two-dimensional materials with unprecedented precision, potentially opening new avenues for designing materials optimized for energy storage, electronics, and filtration.
The technique focuses on a family of materials known as MAX phases and their derivatives, MXenes. MAX phases are composed of three distinct layers: a transition metal (M), an element such as aluminum (A), and carbon or nitrogen (X). Traditionally, producing MXenes involves etching away the A layer using strong acids, a process pioneered by Drexel’s team in 2011. This yields atomically thin sheets with remarkable electrical conductivity, chemical stability, and tunable surface chemistry. However, the conventional method offers limited control over the final composition and properties.
The new process employs what the researchers call “chemical scissors” — reactive agents designed to break specific atomic bonds. While chemical scissors have been used in organic chemistry for over a decade to cleave carbon-hydrogen bonds, this adaptation targets the robust bonds within layered inorganic structures. “This research opens a new era of materials science, enabling atomistic engineering of two-dimensional and layered materials,” said Yury Gogotsi, PhD, Distinguished University Professor at Drexel. “We are showing a way to assemble and disassemble these materials like LEGO blocks, which will lead to the development of exciting new materials that have not even been predicted to be able to exist until now.”
The process begins with Lewis acidic molten salt (LAMS) etching, which removes the A layer and simultaneously replaces it with another element, such as chlorine. This substitution alters the chemical environment, making it possible to slice apart the remaining layers using a second set of chemical scissors composed of metals like zinc. Once separated, these layers can be recombined through intercalation — inserting new elements between them — to construct entirely new MAX phases. These custom-built precursors can then be converted into MXenes with tailored properties.
“This process is like making a surgical cut of the MAX structure, peeling apart the layers and then reconstructing it with new and different metal layers,” Gogotsi explained. “In addition to being able to produce new and unusual chemistries, which is interesting fundamentally, we can also make new and different MAX phases and use them to produce MXenes that are tailored to optimize various properties.”
The team demonstrated that this approach can yield MXenes capable of hosting “guest atoms” that were previously incompatible with the conventional synthesis route. This capability significantly expands the chemical diversity of MXenes, potentially enabling materials with novel electronic, mechanical, or catalytic behaviors. “We expect this work to lead to a major expansion of the already very large space of layered and two-dimensional materials,” Gogotsi said. “New MXenes that could not be produced from conventional MAX precursors are becoming possible. Of course, new materials with unusual structure and properties are expected to enable new technologies.”
MXenes have already attracted attention for applications ranging from high-performance batteries and supercapacitors to electromagnetic shielding and water purification. The ability to fine-tune their composition at the atomic level could accelerate their integration into aerospace components, advanced robotics, and next-generation vehicles, where lightweight, durable, and multifunctional materials are in high demand.
The researchers plan to extend the method to delaminate two- and three-dimensional layered carbides, as well as metal-intercalated carbides, into single- and few-layer nanosheets. Characterizing these structures will help identify optimal configurations for specific applications, bridging the gap between fundamental materials science and practical engineering solutions.
Participants in the study included Haoming Ding, Youbing Li, Mian Li, Ke Chen, Kun Liang, Shiyu Du, and Zhifang Chai from the Chinese Academy of Sciences; Guoxin Chen from Quinwan Institute of CNiTech; and Jun Lu, Justinas Palisaitis, Per O. Å. Persson, Per Eklund, and Lars Hultman from Linköping University.