Liquid gallium turns sunlight and seawater into clean hydrogen

Researchers at the University of Sydney have developed an innovative, sunlight-powered method to produce clean hydrogen from both freshwater and seawater using liquid gallium. This approach overcomes key challenges in green hydrogen production, such as the need for purified water and high energy consumption. The process involves suspending liquid gallium— a metal that melts slightly above room temperature—in water and exposing it to light, which triggers a surface reaction that releases hydrogen while forming gallium oxyhydroxide. Importantly, the method requires no external electricity or complex infrastructure, making it efficient and potentially scalable, with a reported maximum efficiency of 12.9 percent. Unlike traditional electrolysis, this gallium-based technique can utilize abundant water sources, including seawater, reducing costs and complexity, which is especially advantageous for coastal or water-scarce regions. The process is also circular: the gallium oxyhydroxide produced can be chemically converted back into gallium and reused for further hydrogen generation. The research team is now working to