Solar-Powered Device Can Recycle Both Climate and Plastic Pollution

Carbon dioxide and single-use plastics are two of the leading pollutants wreaking havoc on Earth’s systems. But what if it was possible to turn them both into something actually useful by channeling the power of the sun?

Researchers at the University of Cambridge announced Monday that they had developed the first-ever solar-powered system that could convert two types of waste into two different chemicals at the same time, in this case, carbon dioxide and plastics. 

“A solar-driven technology that could help to address plastic pollution and greenhouse gases at the same time could be a game-changer in the development of a circular economy,” study co-first author Subhajit Bhattacharjee said in a university press release.

The research, published in Nature Synthesis Monday, demonstrates the effectiveness of what its authors called a “promising and sustainable technology.” The device can convert both pollutants into a range of products that could be useful to industry, PV Magazine reported. For example, in tests of the device, carbon dioxide was converted into syngas, which is used in sustainable fuel, according to the press release. PET plastic bottles, on the other hand, were converted into common cosmetics ingredient glycolic acid. 

However, the researchers wanted the device to be adaptable to different uses. Therefore, they designed it so that the different end products can be generated by using different catalysis in the reactor, according to PV Magazine. The catalyst molecular cobalt porphyrin turned carbon dioxide into carbon monoxide, a formate dehydrogenase enzyme turned it into formate and an alloy of Cu91In9 generated the syngas, according to the study.

“What’s so special about this system is the versatility and tuneability – we’re making fairly simple carbon-based molecules right now, but in future, we could be able to tune the system to make far more complex products, just by changing the catalyst,” Bhattacharjee said in the release.

The system is also unique because it uses perovskite instead of silicon to absorb the light that powers the reactor, PV Magazine explained. This was part of what allowed the researchers to use different catalysts. 

Turning waste into fuel is the goal of many scientists looking to resolve environmental problems, and there are other solar-powered options for recycling either plastics or carbon dioxide, but none that do both at once, the press release said.

Over the next five years, the team plans to work on using the reactor to generate more complex products. Ultimately, they think it would be possible to build a solar-powered recycling plant. 

“Developing a circular economy, where we make useful things from waste instead of throwing it into landfill, is vital if we’re going to meaningfully address the climate crisis and protect the natural world,” study senior author and Yusuf Hamied Department of Chemistry Professor Erwin Reisner–who also leads the  Cambridge Circular Plastics Centre (CirPlas) – said in the press release. “And powering these solutions using the Sun means that we’re doing it cleanly and sustainably.”