This week, researchers at ETH Zurich have unveiled a groundbreaking method for capturing greenhouse gases using light. The new process, developed by a team led by Maria Lukatskaya, professor of electrochemical energy systems, utilizes the differences between dark and light to enable a cyclic process for the capture and release of CO2.

The urgency to combat global warming has led to a critical need for reducing greenhouse gas emissions. In addition to transitioning away from fossil fuels and adopting more energy-efficient technologies, it is essential to capture large quantities of CO2 from the atmosphere and either store it underground or use it as a carbon-neutral feed material in industry. However, current carbon capture technologies are energy-intensive and costly.

The researchers at ETH Zurich are addressing this challenge by harnessing the power of light. Their innovative approach aims to derive the energy required for carbon capture from the sun, offering a more sustainable and cost-effective solution. The findings of their work have been published in Chemistry of Materials.

The method developed by the ETH Zurich team involves leveraging the reversible chemical reaction of CO2 in acidic and alkaline aqueous liquids. By introducing photoacids, which react to light, into the liquid, the researchers are able to control its acidity. When the liquid is irradiated with light, it becomes acidic, causing the carbonates formed from CO2 to transform back into CO2, which can then be collected. Once the CO2 has been effectively captured, the researchers can reset the process by switching off the light, allowing the liquid to return to its original state and prepare for the next cycle of CO2 capture.

While the concept proved promising, the researchers encountered a challenge with the stability of the photoacids in water during their initial experiments. This led them to explore different mixtures to optimize the performance of the photoacids in the liquid, ultimately refining the method for greater efficiency and reliability.

The development of this light-based carbon capture method represents a significant advancement in the pursuit of sustainable and efficient solutions for mitigating climate change. By tapping into the potential of light to drive the capture and release of CO2, the researchers at ETH Zurich are pioneering a novel approach that holds promise for revolutionizing carbon capture technologies.