Cambridge University research group converts plastic waste into hydrogen using sunlight

How the solar reactor works

The researchers see a dual benefit: on the one hand, plastic waste is converted into recyclable materials, and on the other, hydrogen is produced, which is considered a clean energy carrier. The reaction takes place under ambient conditions, without high temperatures or strong pressure, which is said to make the process more energy-efficient than conventional recycling methods.

Speaking to the APA, Reisner emphasised that the tests under real-world conditions marked an important step. "Wenn dann die Sonne darauf scheint, produziert der Reaktor Wasserstoff und das Plastik wird in organische Moleküle überführt," he said. At the same time, he acknowledged that the technology still needs further development.

A key goal of the upcoming work is to improve the semiconductors used. "Wir arbeiten daran, Halbleiter zu entwickeln, die mehr vom solaren Spektrum verwenden können," said the chemist. This is intended to increase the yield of hydrogen per hour of sunlight.

Patent and next steps

According to the information provided, the process has been patented by Cambridge Enterprise, the university's innovation arm. This means the invention is secured intellectual property of the university, paving the way for possible industrial exploitation. No concrete licensees or production plans were initially announced.

The research work was published in the journal Nature and is part of a series of attempts to make photocatalysis usable for plastic recycling. Other teams worldwide are experimenting with similar approaches, such as the use of bacteria or photothermal materials. Reisner's group stands out due to the comparatively simple setup, which does not require any rare raw materials.

Classification in the research landscape

Environmental organisations see such technologies as a possible building block of a circular economy, but at the same time warn against exaggerated expectations. As long as global plastic production continues to rise, the prevention and reduction of plastic waste remains the most important measure. Solar-powered reactors could, however, contribute to making better use of existing waste streams.

Reisner announced that the system would be tested on a larger scale in the coming years. This also includes trials with different types of plastic, including mixed waste as it commonly occurs in practice. The goal is to move the reactor from the laboratory plate towards an industrial pilot plant.

The University of Cambridge sees the process as an example of how basic research can lead to concrete applications. With the patenting and the cooperation with Cambridge Enterprise, it wants to accelerate the transfer to industry. Reisner spoke of an "important step", but emphasised that numerous technical questions remain open.