Titanium dioxide key to solar water-splitter

‘So called ‘solar fuels’ like hydrogen offer a solution to how to store energy for night time use by taking a cue from natural photosynthesis’ said lead researcher Tom Meyer, Arey Distinguished Professor of Chemistry at UNC’s College of Arts and Sciences. ‘Our new findings may provide a last major piece of a puzzle for a new way to store the sun’s energy – it could be a tipping point for a solar energy future.’

Dubbed a dye-sensitised photoelectrosynthesis cell (DSPEC), the new system - designed by Meyer and colleagues at UNC and Greg Parson’s group at North Carolina State University - generates hydrogen fuel by using the sun’s energy to split water into its component parts. After the split, hydrogen is sequestered and stored, while the oxygen by-product is released into the air.

‘But splitting water is extremely difficult to do,’ Meyer said in a statement. ‘You need to take four electrons away from two water molecules, transfer them somewhere else, and make hydrogen, and, once you have done that, keep the hydrogen and oxygen separated. How to design molecules capable of doing that is a really big challenge that we’ve begun to overcome.’