Image courtesy of Fuding Lin and Shannon Boettcher
To one day design cells that mimic trees ability to turn sunlight and water into fuel, scientists
at the University of Oregon devised a new technique that allows them to “see” a key interface
in the cells – the interface between the semiconductor that absorbs sunlight and generates
electricity with the catalyst that uses the electricity to create fuel.
(December 5, 2015) With the help of a new method called "dual-electrode photoelectrochemistry," University of Oregon scientists have provided new insight into how solar water-splitting cells work. An important and overlooked parameter, they report, is the ion-permeability of electrocatalysts used in water-splitting devices.
Their discovery could help replace a trial-and-error approach to paring electrocatalysts with semiconductors with an efficient method for using sunlight to separate hydrogen and oxygen from water to generate renewable energy, says Shannon W. Boettcher, professor of chemistry and head of the Solar Materials and Electrochemistry Laboratory in the UO's Materials Science Institute.
The research is described in a paper placed online Dec. 1 in advance of regular publication in the journal Nature Materials.
Solar water-splitting cells, which mimic photosynthesis, require at least two different types of materials: a semiconductor that absorbs sunlight and generates excited electrons and an electrocatalyst, typically a very thin film of a metal oxide that contains elements such as nickel, iron and oxygen, which serves to accelerate the rate at which electrons move on and off water molecules that are getting split into hydrogen and oxygen.