Breakthrough in Creating Fuel from Sunlight Puts Us Closer to Carbon-Neutral Energy

Breakthrough in Creating Fuel from Sunlight Puts Us Closer to Carbon-Neutral Energy

Recent leaps in technology represent an important step forward in unlocking artificial photosynthesis.

Photo by Johannes Plenio on Unsplash

Since the beginning of life on Earth, plants have been naturally converting sunlight into energy. This photosynthesis process that's effortless for them has been anything but for scientists who have been trying to achieve artificial photosynthesis for the last half a century with the goal of creating a carbon-neutral fuel. Such a fuel could be a gamechanger — rather than putting CO2 back into the atmosphere like traditional fuels do, it would take CO2 out of the atmosphere and convert it into usable energy.

If given the option between a carbon-neutral fuel at the gas station and a fuel that produces carbon dioxide in spades -- and if costs and effectiveness were equal --who wouldn't choose the one best for the planet? That's the endgame scientists are after. A consumer switch to clean fuel could have a huge impact on our global CO2 emissions.


Up until this point, the methods used to make liquid fuel from atmospheric CO2 have been expensive, not efficient enough to really get off the ground, and often resulted in unwanted byproducts. But now, a new technology may be the key to unlocking the full potential of artificial photosynthesis. At the very least, it's a step forward and could help make a dent in atmospheric CO2 reduction.

"It's an important breakthrough in artificial photosynthesis," says Qian Wang, a researcher in the Department of Chemistry at Cambridge University and lead author on a recent study published in Nature about an innovation she calls "photosheets."

The latest version of the artificial leaf directly produces liquid fuel, which is easier to transport and use commercially.

These photosheets convert CO2, sunlight, and water into a carbon-neutral liquid fuel called formic acid without the aid of electricity. They're made of semiconductor powders that absorb sunlight. When in the presence of water and CO2, the electrons in the powders become excited and join with the CO2 and protons from the water molecules, reducing the CO2 in the process. The chemical reaction results in the production of formic acid, which can be used directly or converted to hydrogen, another clean energy fuel.

In the past, it's been difficult to reduce CO2 without creating a lot of unwanted byproducts. According to Wang, this new conversion process achieves the reduction and fuel creation with almost no byproducts.

The Cambridge team's new technology is a first and certainly momentous, but they're far from the only team to have produced fuel from CO2 using some form of artificial photosynthesis. More and more scientists are aiming to perfect the method in hopes of producing a truly sustainable, photosynthetic fuel capable of lowering carbon emissions.

Thanks to advancements in nanoscience, which has led to better control of materials, more successes are emerging. A team at the University of Illinois at Urbana-Champaign, for example, used gold nanoparticles as the photocatalysts in their process.

"My group demonstrated that you could actually use gold nanoparticles both as a light absorber and a catalyst in the process of converting carbon dioxide to hydrocarbons such as methane, ethane and propane fuels," says professor Prashant Jain, co-author of the study. Not only are gold nanoparticles great at absorbing light, they don't degrade as quickly as other metals, which makes them more sustainable.

That said, Jain's team, like every other research team working on artificial photosynthesis including the Cambridge team, is grappling with efficiency issues. Jain says that all parts of the process need to be optimized so the reaction can happen as quickly as possible.

"You can't just improve one [aspect], because that can lead to a decrease in performance in some other aspects," Jain explains.

The Cambridge team is currently experimenting with a range of catalysts to improve their device's stability and efficiency. Virgil Andrei, who is working on an artificial leaf design that was developed at Cambridge in 2019, was recently able to improve the performance and selectivity of the device. Now the leaf's solar-to-CO2 energy conversion efficiency is 0.2%, twice its previous efficiency.

The latest version also directly produces liquid fuel, which is easier to transport and use commercially.

In determining a method of fuel production's efficiency, one must consider how sustainable it is at every stage. That involves calculating whenever excess energy is needed to complete a step. According to Jain, in order to use CO2 for fuel production, you have to condense the CO2, which takes energy. And on the fuel production side, once the chemical reaction has created your byproducts, they need to be separated, which also takes energy.

To be truly sustainable, each part of the conversion system also needs to be durable. If parts need to be replaced often, or regularly maintained, that counts against it. Then you have to account for the system's reuse cycle. If you extract CO2 from the environment and convert it into fuel that's then put into a fuel cell, it's going to release CO2 at the other end. In order to create a fully green, carbon-neutral fuel source, that same amount of CO2 needs to be trapped and reintroduced back into the fuel conversion system.

"The cycle continues, and at each point, you will see a loss in efficiency, and depending on how much you [may also] see a loss in yield," says Jain. "And depending on what those efficiencies are at each one of those points will determine whether or not this process can be sustainable."

The science is at least a decade away from offering a competitive sustainable fuel option at scale. Streamlining a process to mimic what plants have perfected over billions of years is no small feat, but an ever-growing community of researchers using rapidly advancing technology is driving progress forward.

Ally Hirschlag
Ally Hirschlag is a Brooklyn-based writer and editor who covers mental health, women's rights, and sustainability among other things. In her spare time, she enjoys baking and channeling her anxiety into satire. You can find more of her work and musings on Facebook and Twitter.
Scientists are working on eye transplants for vision loss. Who will sign up?

Often called the window to the soul, the eyes are more sacred than other body parts, at least for some.

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Awash in a fluid finely calibrated to keep it alive, a human eye rests inside a transparent cubic device. This ECaBox, or Eyes in a Care Box, is a one-of-a-kind system built by scientists at Barcelona’s Centre for Genomic Regulation (CRG). Their goal is to preserve human eyes for transplantation and related research.

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Stav Dimitropoulos
Stav Dimitropoulos's features have appeared in major outlets such as the BBC, National Geographic, Scientific American, Nature, Popular Mechanics, Science, Runner’s World, and more. Follow her on Facebook or Twitter @TheyCallMeStav.
As Our AI Systems Get Better, So Must We

In order to build the future we want, we must also become ever better humans, explains the futurist Jamie Metzl in this opinion essay.

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As the power and capability of our AI systems increase by the day, the essential question we now face is what constitutes peak human. If we stay where we are while the AI systems we are unleashing continually get better, they will meet and then exceed our capabilities in an ever-growing number of domains. But while some technology visionaries like Elon Musk call for us to slow down the development of AI systems to buy time, this approach alone will simply not work in our hyper-competitive world, particularly when the potential benefits of AI are so great and our frameworks for global governance are so weak. In order to build the future we want, we must also become ever better humans.

The list of activities we once saw as uniquely human where AIs have now surpassed us is long and growing. First, AI systems could beat our best chess players, then our best Go players, then our best champions of multi-player poker. They can see patterns far better than we can, generate medical and other hypotheses most human specialists miss, predict and map out new cellular structures, and even generate beautiful, and, yes, creative, art.

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Jamie Metzl
Jamie Metzl is a leading futurist and the Founder and Chair of OneShared.World, https://www.oneshared.world/. His book, The Great Biohack: Recasting Life in an Age of Revolutionary Technology, will be published in May 2024 by Timber/Hachette. www.jamiemetzl.com.