New approach to synthesis promises sustainable manufacturing

James Tour’s lab at Rice University has developed a new method known as flash-within-flash (FWF) Joule heating that could transform the synthesis of high-quality solid materials, offering a cleaner, faster, and more sustainable manufacturing process. The results were published in Chemistry of nature August 8th.

Traditionally, solid-state materials synthesis is a time-consuming and energy-intensive process, often accompanied by the production of harmful byproducts. But FWF enables gram-scale production of diverse compounds in seconds while reducing energy, water, and greenhouse gas emissions by more than 50%, setting a new standard for sustainable manufacturing.

This innovative research builds on Tour’s 2020 development of waste disposal and recycling applications using flash Joule heating, a technique that passes a current through a moderately resistive material to rapidly heat it to more than 3,000 degrees Celsius (more than 5,000 degrees Fahrenheit) and transform it into other substances.

“The key is that we were previously producing carbon and a few other compounds that could be conductive,” says Tour, the TT and WF Chao Professor of Chemistry and professor of materials science and nanoengineering. “Now we can flash synthesize the rest of the periodic table. That’s a big step forward.”

The success of FWF lies in its ability to overcome the conductivity limitations of conventional flash Joule heating methods. The team, including Chi Hun “Will” Choi, a doctoral student, and Yimo Han, an assistant professor of chemistry, materials science and nanoengineering, incorporated an external flash heating vessel filled with metallurgical coke and a semi-closed internal reactor containing the target reactants. FWF generates intense heat of about 2,000 degrees Celsius, which rapidly converts the reactants into high-quality materials through thermal conduction.

This new approach enables the synthesis of more than 20 unique, phase-selective materials with high purity and consistency, according to the study. The versatility and scalability of FWF are ideal for the production of next-generation semiconductor materials such as molybdenum diselenide (MoSe2), tungsten diselenide, and alpha-phase indium selenide, which are notoriously difficult to synthesize using conventional techniques.

“Unlike traditional methods, FWF does not require the addition of conductive agents, which reduces the formation of impurities and by-products,” Choi said.

This advance opens up new opportunities in electronics, catalysis, energy and fundamental research. It also offers a sustainable solution for the manufacturing of a wide range of materials. In addition, FWF has the potential to revolutionize industries such as aerospace, where materials such as MoSe2 made from FWF exhibit superior performance as solid-state lubricants.

“FWF represents a step change in materials synthesis,” Han said. “By providing a scalable and sustainable method to produce high-quality, strong materials, it addresses manufacturing hurdles while paving the way for a cleaner, more efficient future.”