Researchers at Tyndall National Institute (Cork, Ireland) are partnering with scientists from Stanford University (Palo Alto, Calif.) and Queen's University Belfast to create the conditions for the efficient splitting of water into hydrogen and oxygen.
The three-year, €1 million project is called Research into Emerging Nanostructured Electrodes for the Splitting of Water’ (RENEW) and it will use semiconductor materials and sunlight to split water up into its constituent atoms without requiring additional energy.
This is a function that is done within the leaves of plants but is hard to engineer. If done efficiently it could be a step towards using sunlight to create hydrogen reserves that could then be used to produce liquid fuels for electricity generation. Previous research has required the presence of ultraviolet light.
The ultimate goal is to get to a point where electrodes can be dropped into water and when the sun comes out they would start to bubble away generating an unlimited, free and completely clean source of hydrogen and oxygen.
Previous work has shown that the stacked structures created in semiconductor devices using atomic layer deposition can perform this function. However the presence of water is caustic to many of these structures. That work has also required ultraviolet light.
RENEW will focus on using natural light and will experiment with a range of semiconducting materials. Key to the process will be creating an impenetrable top layer that can withstand water’s corrosive effects.
Professor Pemble said: "Professor McIntyre has shown that if you put the right metal on the surface of a silicon stack and provide light, then you can get it to oxidise water to give oxygen. Then, on another electrode connected to it – perhaps a platinum wire – the electrons that we have gained can be used to reduce water, and this produces hydrogen. So it only requires the sunlight to fall on this stack of layers where the water oxidation takes place. Then, according to Prof Andrew Mills, who is an acknowledged expert on photocatalysis, 'the rest of the process is driven by the electrochemistry'."
Related links and articles: