US scientists have take inspiration from plants to create a water-based solar cells to convert light into electricity.
Plants efficiently use light to initiate reactions that produce energy in a process known as photosynthesis. Now Orlin Velev and colleagues at North Carolina State University, have created a hydrogel device to mimic this process to create electricity.
The device uses a 98 per cent water hydrogel doped with two photoactive dyes (9,10-dimethoxy-2-anthracenesulfonic acid and ruthenium trisbipyridine).The gel is layered between a copper foil electrode coated with carbon black and graphite and an indium tin oxide-coated plastic substrate serving as the other electrode. The dyes absorb light exciting the electrons into a higher energy state. Transport of the dyes through the hydrogel allows electrons and electron holes to be transferred to the two electrodes completing the circuit and generating a current.