A group of Korean scientists from Seoul National University has developed an innovative green technology that transforms plastic waste into clean hydrogen fuel using sunlight and water. Led by Professors Dae-Hyeong Kim and Taeghwan Hyeon, the researchers created a photocatalytic system that can generate hydrogen from PET bottles. By encapsulating the photocatalyst in a hydrogel polymer, the system floats on water and remains active even in challenging environmental conditions. This breakthrough addresses the limitations of traditional hydrogen production methods like methane steam reforming, offering a cleaner and more sustainable alternative using sunlight. The research team designed a system that places the reaction at the air-water interface to enhance stability and prevent issues like reverse reactions and catalyst degradation. Their system remained stable for over two months, even in harsh alkaline conditions and different water sources. Tests conducted with a one-square-meter device outdoors showed promising results in generating hydrogen from dissolved PET bottle waste. The scalability of the technology hints at the potential for cost-effective, carbon-free hydrogen production at a larger scale. This new technology not only produces clean hydrogen but also breaks down plastics like PET into valuable byproducts such as terephthalic acid and ethylene glycol. The study, published in Nature Nanotechnology, marks a significant advancement in the utilization of plastic waste for energy generation, contributing to both environmental protection and meeting clean energy demands. The researchers believe that their work could serve as a crucial step towards a hydrogen-powered, carbon-neutral society, providing a practical solution to environmental pollution and energy sustainability.