Lasers and 2D materials could solve the global plastic crisis

A global research team led by Texas engineers has developed a way to destroy molecules in plastics and other materials with a laser to break them down into their smallest parts for later reuse.

This discovery, which involves depositing these materials on two-dimensional materials called transition metal dichalcogenides and then igniting them, has the potential to improve how we dispose of plastics that are nearly impossible to break down with current technologies.

“By harnessing these unique reactions, we can explore new pathways to transform environmental pollutants into valuable, reusable chemicals, contributing to the development of a more sustainable and circular economy,” said Yuebing Zheng, a professor in the Walker Department of Mechanical Engineering in the Cockrell School of Engineering and one of the project leaders. “This discovery has important implications for addressing environmental challenges and advancing the field of green chemistry.”

The research was recently published in Nature CommunicationsThe team includes researchers from the University of California, Berkeley, Tohoku University in Japan, Lawrence Berkeley National Laboratory, Baylor University and Pennsylvania State University.

Plastic pollution has become a global environmental crisis. Millions of tons of plastic waste accumulate in landfills and oceans each year. Conventional methods of degrading plastic are often energy-intensive, environmentally harmful, and inefficient. Researchers plan to use this new discovery to develop efficient plastic recycling technologies to reduce pollution.

The researchers used low-power light to break the chemical bonds in the plastics and create new chemical bonds that transformed the materials into luminescent carbon dots. Carbon-based nanomaterials are in high demand because of their many capabilities, and these dots could potentially be used as memory storage devices in next-generation computing devices.

“It’s exciting to be able to potentially take plastic that, on its own, might never decompose and turn it into something useful for many different industries,” said Jingang Li, a postdoctoral student at the University of California, Berkeley, who began the research at UT.

This specific reaction is called CH activation, where the carbon-hydrogen bonds of an organic molecule are selectively broken and transformed into a new chemical bond. In this research, the two-dimensional materials catalyzed this reaction which led to the transformation of hydrogen molecules into gas. This paved the way for the carbon molecules to bond with each other and form the information storage points.

Further research and development is needed to optimize the CH activation process by light and scale it up to industrial scale. However, this study represents a significant step forward in the quest for sustainable solutions for plastic waste management.

The light-induced CH activation process demonstrated in this study can be applied to many long-chain organic compounds, including polyethylene and surfactants commonly used in nanomaterial systems.

The research was funded by various institutions, including the National Institutes of Health, the National Science Foundation, the Japan Society for the Promotion of Science, the Hirose Foundation, and the National Natural Science Foundation of China.

The research team includes Deji Akinwande and Yuqian Gu of UT’s Chandra Family Department of Electrical and Computer Engineering; Zhihan Chen, Zilong Wu and Suichu Huang of UT’s Materials Science and Engineering Program; Hao Li, Di Zhang and Zhongyuan Guo of Tohoku University in Japan; Brian Blankenship, Min Chen and Costas P. Grigoropoulos of the University of California, Berkeley; Xi Jiang, Robert Kostecki and Andrew M. Minor of Lawrence Berkeley National Laboratory; Jonathan M. Larson of Baylor University; and Haoyue Zhu, Tianyi Zhang, Mauricio Terrones and Joan M. Redwing of Pennsylvania State University.