Researchers at The University of Manchester have discovered another new and unexpected physical effect in graphene – membranes that could be used in devices to artificially mimic photosynthesis.
Researchers recently found that it is also permeable to thermal protons, which means that it might be employed as a proton-conducting membrane in various technology applications.
To find out how light affects the behaviour of protons permeating through the carbon sheet, a team led by Dr. Marcelo Lozada-Hidalgo and Professor Sir Andre Geim fabricated pristine graphene membranes and decorated them on one side with platinum nanoparticles.
The Manchester scientists were surprised to find that the proton conductivity of these membranes was enhanced 10 times when they were illuminated with sunlight. Scientists around the world are busy looking into how to directly use solar energy to produce renewable fuels by mimicking photosynthesis in plants.
Currently, researchers use a mixture of proton and electron-conducting polymers to make such structures, but these require some important trade-offs that could be avoided by using graphene.
Photodetectors typically harvest light to produce just electricity but graphene membranes produce both electricity and, as a by-product, hydrogen.