Researchers at the University of Oxford's Department of Engineering Science have developed a groundbreaking method for green hydrogen production by bio-engineering bacteria into 'hydrogen nanoreactors'. This approach aims to address the limitations of current industrial hydrogen production, which heavily rely on fossil fuels and contribute to CO2 emissions. The team engineered the bacterium Shewanella oneidensis to enhance electron and proton transfer for efficient hydrogen production. By introducing a light-activated electron pump and nanoparticles to boost electron transfer, the engineered strain achieved a significant increase in hydrogen yield compared to a non-engineered strain. The system could potentially be scaled up to create 'artificial leaves', where the engineered bacteria cells would be printed onto carbon fibre cloth, producing hydrogen when exposed to sunlight. The study, published in Proceedings of the National Academy of Science, demonstrates the potential of biocatalysts for clean energy production. Lead author Professor Wei Huang highlighted the advantages of the biocatalyst, including safety, renewability, and lower production costs, enhancing long-term economic viability. The researchers' innovative approach offers a promising pathway towards decarbonizing 'hard to electrify' sectors such as aviation and shipping through the use of green hydrogen.