Revolutionary technique to more efficiently generate hydrogen from water

A team of researchers from the National University of Singapore (NUS) have made a chance scientific discovery that could potentially revolutionize the way water is broken down to release hydrogen gas, a crucial 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 Department of Materials Science and Engineering at NUS College of Design and Engineering (NUS CDE), found that the light may trigger a new mechanism in a catalytic material widely used in water electrolysis, where water is broken down 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 Sustainability Institute for Chemicals, Energy and the Environment of the Agency for Science, Technology and Research (A*STAR); Dr. Yu Zhigen from the Institute of High Performance Computing under A*STAR; and Dr. Wang Hao from the Department of Mechanical Engineering at NUS CDE.

“We found that the redox center of the electrocatalytic reaction is switched between metal and oxygen, triggered by light,” Assoc said. Professor Xue. “This greatly improves the efficiency of water electrolysis.”

The new discovery has the potential to open up new, more efficient industrial methods of producing hydrogen and bring this environmentally friendly fuel source within reach of more people and industries.

Assoc. Professor Xue and his team detailed their finding in a research paper published in the journal Nature on October 26, 2022.

The accidental breakthrough

Under normal circumstances, Assoc. Professor Xue and his team may not have been able to come across such a breakthrough discovery. But an accidental tripping of the power to the ceiling lights in his lab nearly three years ago allowed them to observe something that the global scientific community has yet to manage to do.

At the time, ceiling lights from Assoc. Professor Xue’s research lab was usually on for 24 hours. One night in 2019 the lights went out due to a power issue. When the researchers returned the next day, they found that the performance of a nickel oxyhydroxide material in the water electrolysis experiment, which had continued in the dark, had dropped by drastically.

“This drop in performance, no one has ever noticed before, because no one has ever experienced it in the dark,” Assoc said. Professor Xue. “Furthermore, the literature says that such a material should not be light-sensitive; light should have no effect on its properties.”

The electrocatalytic mechanism in the electrolysis of water is a much studied topic, while the nickel-based material is a very common catalytic material. Therefore, in order to establish that they were on the verge of discovering something revolutionary, Assoc. Professor Xue and his team embarked on many repeated experiments. They delved into the mechanisms behind such a phenomenon. They even repeated the experiment outside of Singapore to make sure their results were consistent.

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

Next steps

With their findings, the team is now working on designing a new way to improve industrial processes for generating hydrogen. Assoc. Professor Xue suggests making water-containing cells transparent, in order to introduce light into the process of separating the water.

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

Food companies use hydrogen gas to turn unsaturated oils and fats into saturated fats, which gives us margarine and butter. Hydrogen is also used to weld metals together as it can generate a high temperature of 4000 degrees Celsius. The petroleum industry uses gas to remove the sulfur content from petroleum.

Additionally, hydrogen can potentially be used as a fuel. Long considered a sustainable fuel, hydrogen produces zero emissions because it burns by reacting with oxygen – no ignition is required, making it a cleaner, greener fuel source. It is also easier to store, which makes it more reliable than solar batteries.

Assoc. Professor Xue is happy that the findings of his research team can contribute to scientific discovery. He thinks the way to develop science is not to keep finding new ways to do what has already been done, but to constantly push the boundaries.

“It is only through the accumulation of new knowledge that we can gradually improve society,” Assoc said. Professor Xue.