Cambridge Scientists Develop a Whole New Way to Harness Energy From Sunlight

Semi artificial photosynthesis takes a cue from plants. 

by James Dennin
Katarzyna Sokó?

One of the more long shot efforts to not only develop more renewable energy, but also to help mitigate climate change by removing carbon dioxide from the atmosphere is a process called artificial photosynthesis. As the name suggests, this field encompasses efforts to do what plants to — split water molecules into energy-bestowing hydrogen and breathable oxygen using natural sunlight — ourselves in a way that’s more energy efficient.

If scientists can figure out how to recreate the process wherein plants convert climate-warming CO2 into clean energy, we could develop theoretically unlimited clean energy, not only for people here on planet Earth, but also for the people who will (hopefully) one day need clean air and energy in order to explore and develop livable structures in space. It’s an ambition that at least dates back to a 1912 Science paper, but there have been hurdles, namely that it requires the use of expensive, often polluting catalysts.

Fortunately, a group of researchers at the St. John’s College at the University of Cambridge say they may have discovered a workaround by successfully splitting the oxygen and hydrogen molecules in water using a mix of natural processes and manmade technologies. It’s a process they call semi-artificial photosynthesis, and they say it could help revolutionize the development of renewable power. Their findings were published Monday in Nature.

“Natural photosynthesis can be considered as the biological blueprint for the conversion of solar energy to chemical energy and solar fuels,” explained first author Katarzyna Sokó in an email to Inverse. “Compared to natural photosynthesis, this new system makes more efficient use of the solar light spectrum, delivers high conversion yields, and bypasses several competing metabolic pathways, which is not achievable using synthetic biology or materials science alone.”

University of Central Florida

What Is Semi Artificial Photosynthesis?

Semi artificial photosynthesis is a relatively new field of research which tries to re-create photosynthesis using a mix of synthetic biology and materials science with an eye to renewable energy applications. The Cambridge study focused on an enzyme found in algae called Hydrogenase, which used to split hydrogen and water molecules in a process that stopped occurring naturally because it’s no longer necessary for algae’s survival.

“Our work … provides the toolbox for developing future semi-artificial systems for energy conversion and ‘re-wiring’ other photosynthetic pathways,” Sokó added. “For example, the semi-artificial tandem system application could be expanded beyond water splitting reaction to photocatalyse a wide range of reactions, such as conversion of the greenhouse gas, CO2 into a fuel.”

For now, the device just a proof of concept. Sokó elaborated that it’s “relatively too fragile” for industrial applications. The most heartening takeaway, she said, might be the fact that so many different researchers with such wildly different areas of expertise were able to collaborate on solving such an important problem.

“It was surprisingly challenging how many different multi-disciplinary fields and areas of expertise were needed to develop this system, including materials science, nanotechnology, inorganic chemistry, synthetic chemistry and biochemistry,” she said. “It took many years of research and collaboration to gain enough knowledge.”

Researchers see innovations like these as essential not just for ensuring a renewable energy future but also for ensuring that space craft of the future can travel long distances. Back in July, an international group of scientists produced a paper about how to conduct photoelectrochemical experiments experiments in zero gravity environments.

The goal of that project is to look for ways that researchers can conduct experiments like that of the Cambridge team, but in Space.

Additional reporting by Sarah Sloat.

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