MXenes, a family of atomically thin materials known for combining high electrical conductivity with chemically active surfaces, may soon become far easier to manufacture. Researchers at Rice University have developed a gas-phase process that converts layered precursor materials into MXenes in less than 30 seconds, replacing the hours- or days-long liquid chemical etching methods traditionally used in production. The advance, reported in Nature Synthesis, uses flash Joule heating and a carefully controlled mixture of chlorine and tetrafluoromethane gases to remove selected atomic layers from the precursor.
MXenes are two-dimensional materials made by selectively stripping elements from a class of layered ceramics known as MAX phases. Their unusual combination of metallic conductivity, mechanical strength, large surface area and chemically tunable surfaces has made them attractive for next-generation electronics, energy storage, catalysis, sensors and protective coatings. Unlike many other two-dimensional materials, MXenes can also be dispersed in liquids and processed into films, inks and composites. Those advantages have fueled intense interest, but manufacturing has remained a major obstacle because conventional synthesis relies on corrosive acids, long reaction times and difficult waste-handling procedures.
A typical MAX phase contains alternating layers of a transition metal and carbon or nitrogen, separated by a third element, commonly aluminum. In a titanium aluminum carbide precursor, for example, titanium and carbon form the structural layers while aluminum occupies the intermediate position. Producing a titanium carbide MXene requires removing the aluminum without seriously damaging the titanium-carbon framework. The resulting sheets are only a few atoms thick, and their exposed surfaces acquire chemical groups that influence how they interact with ions, molecules and other materials. Achieving that transformation requires atomic-level selectivity: an etchant must attack the targeted layer while preserving the conductive backbone.
The established approach, known as liquid-phase chemical etching, generally uses hydrofluoric acid or fluoride-containing reagents. The acid penetrates the MAX material and dissolves the aluminum layer through a sequence of reactions that can take 12 to 24 hours or longer. Additional washing and treatment steps are then needed to remove residual chemicals and adjust the surface chemistry. Although this route has enabled much of the field’s progress, it produces hazardous waste and can expose researchers and manufacturers to highly toxic substances, including hydrogen fluoride. The lengthy process also increases energy, labor and equipment costs, limiting the ability to produce MXenes at industrial scale.
The Rice team sought a faster alternative by adapting flash Joule heating, a technique developed in James Tour’s laboratory. In flash Joule heating, an electrical pulse passes through a material, rapidly raising its temperature to extreme levels in a fraction of a second. The method has previously been used to transform carbon-rich feedstocks and process other difficult materials. In the new work, Shichen Xu, a postdoctoral researcher in the Tour lab, investigated whether the same ultrafast thermal approach could accelerate MXene synthesis. Rather than immersing the MAX phase in an acid solution, the researchers heated it rapidly and introduced reactive gases into the system.
The gas mixture contained chlorine and tetrafluoromethane, a fluorine-containing compound. Under the intense thermal conditions, these gases reacted with the MAX phase and selectively removed the aluminum layers. The chemistry effectively transferred the etching environment from a liquid solution to a controlled gas phase, while the rapid heating shortened the reaction to less than half a minute. By adjusting the composition of the gas mixture and the time for which the material was exposed, the researchers could alter the extent of etching. This control is particularly important because excessive reaction can attack the transition-metal layers or degrade the fragile two-dimensional structure.
The gas-phase process may offer more than a simple increase in speed. In a liquid system, the etchant must diffuse through a solvent and into the layered solid, while the reaction products and residual chemicals must later be separated through washing. Gas-phase chemistry can provide a more direct route to the exposed surfaces of the precursor, and the absence of a large liquid bath could simplify some aspects of processing and waste management. The researchers say that a properly engineered system could reduce the hazards associated with large volumes of hydrofluoric acid and toxic byproducts. However, chlorine and fluorinated gases are themselves hazardous, meaning that industrial adoption would require sealed reactors, precise gas monitoring and robust containment.
The study also revealed that the new method can display different efficiencies and selectivities depending on the material and etching conditions. That flexibility could allow researchers to tune the composition and surface terminations of MXenes rather than treating etching as a single, fixed operation. Surface terminations, such as fluorine-, oxygen- or hydroxyl-containing groups, influence electrical behavior, wettability, catalytic activity and interactions with ions. Controlling them is essential for designing MXenes for particular applications. A material optimized for electromagnetic shielding, for example, may require different surface chemistry from one intended for catalysis or electrochemical energy storage.
The implications reach beyond a faster laboratory protocol. MXenes are being explored for conductive coatings, flexible and miniature electronics, chemical sensors, batteries, supercapacitors, catalysts and aerospace materials that must withstand demanding environments. Their conductivity can support rapid charge transport, while their high surface area provides abundant sites for chemical reactions or interactions with surrounding molecules. If the Rice process can be scaled while maintaining uniformity and safety, it could lower production barriers for these technologies and make systematic experimentation with different MXene compositions more practical. The work also demonstrates how flash Joule heating can be paired with gas-phase reactions to manufacture advanced materials at speeds that conventional wet chemistry cannot easily match.
The researchers emphasize that the method is not simply a faster version of acid etching but a different manufacturing strategy based on rapid thermal activation and controllable gaseous chemistry. Further development will be needed to determine how broadly it applies across the large family of MAX phases, how consistently it produces defect-free sheets, and how its energy use compares with established methods at industrial scale. The team’s results nevertheless point toward a more rapid, tunable and potentially scalable route to MXenes. By replacing prolonged acid treatment with a reaction completed in seconds, the process could help move these atomically thin materials from specialized laboratories toward practical electronic, catalytic and aerospace applications.
Subject of Research: Rapid gas-phase synthesis of MXenes using flash Joule heating
Article Title: Flash Joule heating for rapid MXenes synthesis
News Publication Date: 10-Aug-2026
Web References: https://profiles.rice.edu/faculty/james-tour ; https://www.nature.com/articles/s44160-026-01132-2
References: Nature Synthesis, DOI: 10.1038/s44160-026-01132-2
Keywords
MXenes, flash Joule heating, gas-phase etching, MAX phases, two-dimensional materials, materials engineering, nanotechnology, electronic materials, aerospace coatings, chemical synthesis
