How lasers and 2D materials could solve the world’s plastic problem

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

The discovery, which involves layering these materials onto two-dimensional materials called transition metal dichalcogenides and then lighting them up, has the potential to improve the way we dispose of plastics that are nearly impossible to break down with today’s technology.

“Using these unique reactions, we can explore new pathways for converting environmental pollutants into valuable, reusable chemicals that will contribute to the development of a more sustainable and circular economy,” said Yuebing Zheng, a professor in the Walker Department of Mechanics at the Cockrell School of Engineering. Engineering and one of the leaders on the project.

“This discovery has significant implications for solving environmental problems and advancing the field of green chemistry.”

The research was recently published in The nature of communication. The 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, with millions of tons of plastic waste piling up in landfills and oceans every year. Common methods of plastic degradation are often energy-intensive, environmentally harmful and ineffective. The researchers anticipate using this new discovery to develop effective plastic recycling technologies to reduce pollution.

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

“It’s exciting to potentially take a plastic that may never break down on its own and turn it into something useful for many different industries,” said Jingang Li, a postdoctoral fellow at the University of California, Berkeley, who initiated the research at UT.

A specific reaction is called CH activation, where carbon-hydrogen bonds in an organic molecule are selectively broken and converted into a new chemical bond. In this research, two-dimensional materials catalyzed this reaction, which turned hydrogen molecules into a gas. This cleared the way for carbon molecules to bond with each other to form information-storing dots.

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

The light-driven 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.