Researchers at Linköping University in Sweden have made significant discoveries in the quest to produce green hydrogen efficiently using sunlight
The team has developed a triple-layered material that enhances the performance of water-splitting reactions, a crucial step in the production of hydrogen.
These new findings have the potential to pave the way for more sustainable energy systems, particularly in the heavy-duty transport sector, where batteries aren’t as practical.
The triple-layer innovation
This new triple-layered material consists of three layers: cubic silicon carbide 3C-SiC), cobalt oxide (Co₃O₄), and a catalytic layer of nickel hydroxide (Ni(OH)₂).
Each of these layers plays a specific role in enhancing the photochemical reaction that splits water (H₂O) into hydrogen (H₂) and oxygen (O₂). When the material is met with sunlight, it generates electric charges that are used to break the bonds in water molecules.
A common challenge in photochemical hydrogen production is the recombination of the positive and negative charges created by sunlight, which can neutralise the effect and reduce the efficiency.
As this material has a unique structure, it can enhance charge separation, thereby increasing the hydrogen yield. The material has already been demonstrated to be eight times more effective than using cubic silicon carbide alone, which is known for its light-absorbing properties.
Cleaner hydrogen production
Currently, most of the hydrogen used globally is grey hydrogen, produced from fossil fuels such as natural gas. By doing this, large amounts of carbon dioxide are emitted (up to 10 tonnes of CO₂ for every tonne of hydrogen produced), making it a significant contributor to climate change.
However, green hydrogen is produced by splitting water using renewable energy sources, such as solar or wind power. This offers a clean alternative for sectors such as aviation, maritime transport, and long-haul trucking, which are challenging to decarbonise with batteries alone.
Future efficiency goals
Although promises have been made regarding green hydrogen, an efficiency barrier exists that hinders its widespread adoption.
Most materials currently under research for solar water splitting achieve efficiencies of only 1–3%. For the technology to become commercially viable, the efficiency must reach at least 10%.
The Linköping University research team believes they are on the right track. With continued development and refinement, they estimate it could take five to ten years to achieve the 10% efficiency goal. This would enable the entire hydrogen production process to be run directly from solar energy, reducing reliance on electricity from other renewable sources and lowering production costs.
The funding and support
This research has been supported by several Swedish research foundations, including the Swedish Foundation for International Cooperation in Research and Higher Education (STINT), the Olle Engkvists Stiftelse, the ÅForsk Foundation, and the Carl Tryggers Stiftelse. Additional support was provided by the Swedish Government’sGovernment’s Strategic Research Area in Advanced Functional Materials (AFM) at Linköping University.
