Researchers have created a process using liquid metals, powered by sunlight, that can produce clean hydrogen from both freshwater and seawater.
The method allows researchers to ‘harvest’ hydrogen molecules from water while also avoiding many of the limits in current hydrogen production methods.
Sydney University lead author & PhD candidate, Luis Campos, said it offers a new avenue of exploration for producing green hydrogen as a sustainable energy source.
“We now have a way of extracting sustainable hydrogen, using seawater, which is easily accessible while relying solely on light for green hydrogen production,” he said.
Senior researcher Professor Kourosh Kalantar-Zadeh, from the School of Chemical and Biomolecular Engineering, said the study is a stunning showcase of how the natural chemistry of liquid metals can create hydrogen.
His team produced hydrogen with a maximum efficiency of 12.9 per cent, and they are currently working to improve this efficiency for commercialisation.
“After we extract hydrogen, the gallium oxyhydroxide can also be reduced back into gallium and reused for future hydrogen production – which we term a circular process,” he said.
Gallium in liquid state is a fascinating element. At room temperature it looks like solid metal, but when heated to body temperature it transforms into liquid metallic puddles.
“Gallium has not been explored before as a way to produce hydrogen at high rates when in contact with water - such a simple observation that was previously ignored,” he said.
Many industries and scientists believe hydrogen is the ideal candidate for a sustainable energy source, contributing significantly to reducing greenhouse gas emissions. ‘Green’ hydrogen, as its name suggests, is made using renewable sources.
Hydrogen is one of the most abundant elements on Earth and can be sourced from a large range of compounds as well, such as water (water has two hydrogen molecules).
When hydrogen burns, it produces no pollutants, only water, but still can generate high levels of energy or power.
Kalantar-Zadeh said there is a global need to commercialise a highly efficient method for producing green hydrogen. “Our process is efficient and easy to scale up,” he said.