Wedoany.com Report on Feb 10th, Researchers at the University of Sydney have developed a novel light-driven technology that uses liquid gallium to produce clean hydrogen from both freshwater and seawater, without the need for external electricity or complex infrastructure. This method overcomes the reliance on purified water and high energy inputs in traditional green hydrogen production, offering a new pathway for sustainable energy.
The core of this technology is liquid gallium, a low-melting-point metal that can directly react with water under light to release hydrogen. By utilizing sunlight or artificial light, the system achieves efficient hydrogen generation, avoiding the expensive catalysts and purification steps required by conventional methods such as electrolysis.
Lead author and PhD candidate Luis Campos said: "We now have a method to sustainably extract hydrogen from seawater, which is readily available, while relying solely on light to produce green hydrogen."
Professor Kourosh Kalantar-Zadeh, a senior researcher at the School of Chemical and Biomolecular Engineering, noted that this research demonstrates the chemical potential of liquid metals. He said: "For a first proof-of-concept, we consider the efficiency of this technology to be highly competitive." The team has achieved an efficiency of up to 12.9% and is working on improvements for commercial applications.
The process has a cyclical nature: after hydrogen is released, the gallium oxyhydroxide produced by the reaction can be reduced back to gallium for reuse. Professor Kalantar-Zadeh said: "After extracting hydrogen, the gallium oxyhydroxide can also be reduced back to gallium for future hydrogen production, which we call a cyclic process."
The researchers emphasize that liquid gallium is solid at room temperature and melts near body temperature. Its oxidation reaction with water under light triggers hydrogen release. Professor Kalantar-Zadeh added: "Gallium has never been explored before as a way to produce hydrogen at a high rate when in contact with water—such a simple observation was previously overlooked."
Co-lead of the project, Dr. François Allioux, said: "Hydrogen provides a clean energy solution for a sustainable future and could play a key role in Australia's international advantage in the hydrogen economy." The team is now focused on improving efficiency and testing medium-scale reactors to advance this light-driven liquid gallium technology toward practical application.
The research, published in the journal *Nature Communications*, provides a scalable solution for producing clean hydrogen using abundant water resources and sunlight.
