When burned or used in fuel cells, hydrogen produces nothing but water, making it an ideal candidate for reducing global carbon emissions. Yet, most of the hydrogen produced today comes from fossil fuels, releasing significant amounts of carbon dioxide into the atmosphere. But now, researchers may have found a way to create carbon-free hydrogen.
A group of researchers, led by Professors Takashi Hisatomi and Kazunari Domen, built a 100-square-meter reactor that uses sunlight and photocatalysts to split water into hydrogen and oxygen. This process bypasses traditional photovoltaic-based methods, which convert sunlight into electricity before splitting water.
The new process relies on sheets of a photocatalyst called SrTiO3:Al, which are submerged in water. Sunlight activates the photocatalyst, splitting water into its molecular components. The gases can then be collected for storage and use. Because it utilizes sunlight for power, this method creates clean, carbon-free hydrogen.
Unlike traditional methods, which lose efficiency in each energy conversion stage, this direct approach minimizes energy losses. The concept itself is groundbreaking. However, efficiency remains a significant hurdle. Current systems achieve just one percent efficiency under simulated sunlight and less than five percent in natural sunlight.
For comparison, state-of-the-art solar cells convert over 20 percent of sunlight into electricity. Improving efficiency is crucial not only to reduce costs but also to make reactors compact enough to practically rely on for carbon-free hydrogen production.
The researchers believe that advancing photocatalyst materials holds the key to scaling up this technology. We’ve also seen other attempts by researchers to bring clean hydrogen to a scalable level using similar techniques. However, they all suffer from the same scaling issue.
Despite its challenges, carbon-free hydrogen production offers a pathway to cleaner energy and industries. With better photocatalysts and increased investment, this technology could revolutionize how we produce hydrogen and accelerate the transition to a carbon-free economy. Something we badly need in our failing fight against climate change.
