A team of Italian scientists has created a sunlight-powered cell that produces pure hydrogen from water.

The team from the University of Milan and the University of Pavia are studying environmentally friendly ways to generate hydrogen, which could in future replace fossil fuels as a major energy source.

The new cell has two compartments filled with water and separated by an electrode made of platinum and titanium dioxide. When it is illuminated, by sunlight or an ordinary lamp, the electrode catalyses the splitting of the water into hydrogen and oxygen gas.

Elena Selli, who led the research, pointed out 'Almost all the photocatalytic water splitting systems described so far imply the evolution of a mixture of hydrogen and oxygen in only one reactor; of course, a separation step would be required prior to any use of hydrogen.' The new design of cell keeps the production of the two gases separate, resulting in streams of hydrogen and oxygen that do not need any purification to be useful.

'Our results demonstrate that hydrogen production from water photocatalytic splitting should be regarded as a practically viable, extremely promising way for clean, low cost and environmentally friendly conversion of solar energy into chemical energy,' said Selli. The team is working on improving the efficiency of the cell by making the titanium dioxide layer of the electrode more sensitive to visible light.

Clare Boothby