Transforming plastic waste into clean hydrogen

June 14, 2025

Scientists have announced a recycling breakthrough that can turn plastic waste into clean hydrogen fuel with the help of sunlight.

Scientists at the Institute for Basic Science (IBS) Center for Nanoparticle Research, led by Professor KIM Dae-Hyeong and Professor HYEON Taeghwan of Seoul National University, have announced the development of the photocatalytic system. The system can produce hydrogen from the PET bottles that are used by millions of people around the globe every day.

Hydrogen is rapidly gaining attention as the new venue for clean energy. However, the most prevalent method for producing it is not very energy-efficient, and it also releases many greenhouse gases into the atmosphere.

Therefore, photocatalytic hydrogen production is a much cleaner alternative for the world.

Photocatalytic hydrogen production

Photocatalytic hydrogen making, which relies on sunlight, faces challenges in maintaining stability under strong light and chemical stress.

The South Korean scientists came up with a new strategy to stabilize the catalyst within a polymer network while placing the reaction site at the interface between air and water.

According to a press release by the team, this setup allowed the system to “avoid common problems such as catalyst loss, poor gas separation, and reverse reactions.” 

It breaks down plastic bottles into byproducts such as ethylene glycol and terephthalic acid, while releasing clean hydrogen into the air.

The scientists have shown that their system worked stably for over two months, even in highly alkaline conditions. The floatable catalyst system can also be put to work in other watery environments, like seawater and tap water.

“The key was engineering a structure that works not only in theory but also under practical outdoor conditions,” explained Dr. Lee Wanghee, a postdoctoral researcher at MIT and co-first author of the study. “Every detail — from material design to the water-air interface — had to be optimized for real-life usability.”

The test system involved a one-square-meter device placed outdoors under natural sunlight that was able to produce hydrogen from dissolved plastic bottles, which had been considered waste.

The plastic waste recycling system can be scaled up

Plastic bottles are one of the major contributors to the growing waste problem in the world. Every day, millions and even billions of these bottles might be getting used, making it an ever-growing problem.

Therefore, a system to turn them into a clean hydrogen source would be like killing two birds with one stone. Managing waste and making clean energy together could really help the world, and simulations predict that the photocatalytic hydrogen production system can be scaled up to make an impact.

Further scale-up simulations showed that the technology can be expanded to 10 or even 100 square meters, offering a pathway toward cost-effective, carbon-free hydrogen production.

“This research opens a new path where plastic waste becomes a valuable energy source,” said Professor Kim Dae-Hyeong. “It’s a meaningful step that tackles both environmental pollution and clean energy demand.”

Professor Hyeon Taeghwan stated, “This work is a rare example of a photocatalytic system that functions reliably in the real world — not just the lab.” He went on to add that it could become a key stepping stone toward a hydrogen-powered, carbon-neutral society.