Sydney Scientists Turn Sunlight and Liquid Metal Into Clean Hydrogen

Liquid Metal Meets Sunlight for Clean Energy

Scientists at the University of Sydney have unveiled a groundbreaking method to produce clean hydrogen from both seawater and freshwater using liquid gallium and sunlight. The research, published in Nature Communications, introduces a circular process that could significantly advance green hydrogen production.

How It Works

Gallium is a remarkable metal that melts near body temperature. When tiny particles of liquid gallium are suspended in water and exposed to sunlight, the light heats the droplets and breaks through the thin oxide layer on their surface. This allows the water molecules to react directly with the liquid metal, producing hydrogen gas and a byproduct called gallium oxyhydroxide. Crucially, that byproduct can be electrochemically converted back into reusable gallium, making the entire process circular.

Promising Efficiency

The team, led by PhD candidate Luis Campos and senior researcher Professor Kourosh Kalantar-Zadeh from the School of Chemical and Biomolecular Engineering, achieved a maximum efficiency of twelve point nine percent. The researchers note this is highly competitive for a first proof-of-concept, pointing out that silicon solar cells started at just six percent efficiency in the nineteen fifties and took decades to surpass ten percent.

Overcoming Traditional Barriers

Conventional water-splitting methods for hydrogen production have long struggled with the need for purified water, high costs, and low yields. The gallium-based approach sidesteps these issues by working with unpurified seawater or freshwater while keeping the core material recoverable and reusable.

Road to Commercialisation

The University of Sydney has filed a patent application for the technology, which was supported by the Australian Research Council. The team is now focused on improving efficiency and plans to build a mid-scale reactor as its next milestone toward commercial deployment. The breakthrough arrives as Australia pursues ambitious green hydrogen targets, aiming to produce over one million tonnes annually by twenty thirty as part of its National Hydrogen Strategy.