An international research team led by Germany’s University of Bayreuth has developed a method for producing green hydrogen directly from seawater–without the use of additional reagents.
As an emission-free energy carrier, green hydrogen is considered by many to be essential for decarbonizing sectors such as transport, industry, and power generation. But production can be costly. One reason is that creating green hydrogen often requires what is known as a sacrificial reagent — a substance that is needed in the development but not part of the final product. A common one is methanol, which is expensive and can be polluting.
These researchers found a way to produce green hydrogen from seawater using sunlight and without the use of a sacrificial reagent. This approach, they said, not only reduces operational costs and chemical waste, but also paves the way for a carbon-free hydrogen economy. They report their findings in the Journal of the American Chemical Society.
Unlike conventional hydrogen derived from fossil fuels, green hydrogen is produced without carbon dioxide emissions. The most common method is electrolysis, in which water is split into hydrogen and oxygen using clean electricity. However, electrolysis requires a significant amount of energy. A promising and resource-efficient alternative is offered by so-called photocatalytic processes, which use sunlight instead of electricity to split water. This involves light-active materials – photocatalysts – that absorb sunlight and provide the energy needed to drive the reaction. So far, methods for large-scale photocatalytic hydrogen production remain under development. Recently, Professor Dr. Shoubhik Das, Chair of Organic Chemistry I at the University of Bayreuth, and his international team have succeeded in developing a photocatalyst capable of clean hydrogen production directly from seawater.
“Our research has produced the first nickel-based photocatalyst that can split seawater directly under sunlight – without any sacrificial reagent or co-catalyst. It achieves hydrogen production rates that surpass most single-component systems studied to date,” says Das. In addition, the photocatalyst is resistant to corrosion by chloride – which is present in high concentrations in seawater – and is unaffected by other seawater constituents.
