The revolutionary technique produces hydrogen from water more efficiently

A team of researchers from the National University of Singapore (NUS) has made a groundbreaking scientific discovery that could potentially revolutionize the way water breaks down to release hydrogen gas – a vital element for many industrial processes.

The team, led by Associate Professor Xue Jun Min, Dr Wang Xiaopeng and Dr Vincent Lee Wee Siang from the NUS College of Design and Engineering (NUS CDE) Department of Materials Science and Engineering, found that light can activate a new mechanism in a catalytic material used extensively in water electrolysis, where water is split into hydrogen and oxygen. The result is a more energy efficient method of obtaining hydrogen.

This breakthrough was achieved in collaboration with Dr Xi Shibo from the Institute for Sustainability in Chemicals, Energy and the Environment under the Agency for Science, Technology and Research (A*STAR). Dr. Yu Zhigen from the Institute for High Performance Computing under A*STAR. and Dr Wang Hao from NUS CDE Department of Mechanical Engineering.

“We discovered that the redox center for the electrocatalytic reaction switches between metal and oxygen, which is activated by light,” said Associate Professor Xue. “This greatly improves the efficiency of water electrolysis.”

The new finding may potentially open up new and more efficient industrial methods of hydrogen production and put this environmentally friendly fuel source within the reach of more people and industries.

Associate Professor Xue and his team detailed their discovery in a research paper published in the prestigious scientific journal Nature on October 26, 2022.

The accidental discovery

Under normal circumstances, Associate Professor Xue and his team might not have been able to come across such a groundbreaking discovery. But an accidental blackout of the ceiling lights in his lab nearly three years ago allowed them to observe something the world’s scientific community has yet to do.

Back then, the ceiling lights in Associate Professor Xue’s research lab were usually on for 24 hours. One night in 2019, the lights went out due to a power outage. When the researchers returned the next day, they found that the performance of a nickel oxyhydroxide-based material in the water electrolysis experiment, which was continued in the dark, had dropped drastically.

“This drop in performance, no one has ever noticed before, because no one has ever done the experiment in the dark,” said Associate Professor Xue. “Also, the literature says that such a material should not be sensitive to light. light should have no effect on its properties.”

The electrocatalytic mechanism in water electrolysis is a very well-researched topic, while nickel-based material is a very common catalyst material. Therefore, in order to establish that they were on the verge of discovering something groundbreaking, Associate Professor Xue and his team began several repeated experiments. They dug deeper into the mechanics behind such a phenomenon. They even repeated the experiment outside of Singapore to ensure their findings were consistent.

Three years later, Associate Professor Xue and his team were finally able to share their findings publicly in a paper.

Next steps

With their findings, the team is now working to design a new way to improve industrial processes for hydrogen production. Associate Professor Xue suggests that the water-containing cells should be transparent so that light is introduced into the water-splitting process.

“This should require less energy in the electrolysis process and it should be much easier to use natural light,” said Associate Professor Xue. “More hydrogen can be produced in less time, with less energy consumed.”

Food companies use hydrogen gas to convert unsaturated oils and fats into saturated ones, which give us margarine and butter. Hydrogen is also used to weld metals together as it can generate a high temperature of 4,000 degrees C. The oil industry uses the gas to remove sulfur content from oil.

In addition, hydrogen can potentially be used as a fuel. Long touted as a sustainable fuel, hydrogen fuel produces no emissions as it burns when it reacts with oxygen – no ignition needed, making it a cleaner and greener fuel source. It’s also easier to store, making it more reliable than solar-powered batteries.

Associate Professor Xue is delighted that his research team’s findings could contribute to scientific discovery. He believes that the way to develop science is not to constantly find new ways to do what has already been done, but to constantly push the boundaries.

“Only through the accumulation of new knowledge can we gradually improve society,” said Associate Professor Xue.

Report: Wang X, Xi S, Huang P, et al. Central role of reversible NiO6 geometrical transformation in oxygen evolution. Nature. Published online 26 Oct 2022: 1-7. doi:10.1038/s41586-022-05296-7

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