Chemists from Leiden University in the Netherlands have managed to find a way to harness 100 times more power from saltwater than any other current membrane. The ultrathin membrane is just one molecule thick and porous.
This discovery could revolutionize the way power is harnessed.
Their findings were published in Nature Nanotechnology on Monday.
Power is generated through the thickness of the membrane
Energy is able to be harnessed through water. When freshwater and saltwater meet, there is an exchange of salt and other particles. Then, when a membrane is placed in this water it's able to generate energy thanks to these moving particles. This is also a method of desalinating water, something that's critical in many drought-stricken nations.
Now, thanks to a team from Leiden University one of these membranes can produce 100 times more power than the current best membranes.
The way these membranes harness power depends on their porousness and how thick the membrane is. Typically, membranes have either been thin or porous, but not both at the same time. Now, thanks to the Leiden chemists, there exists a membrane that is simultaneously porous and thin. This is how it harnesses so much more power.
The new membrane
Leiden University researchers and authors of this study, Xue Liu and Grégory Schneider, created a membrane that is similar to graphene. It is a large and flat membrane that's purely made up of carbon atoms.
Liu said "The membrane we’ve created is only two nanometres thick and permeable to potassium ions. We can change the properties of the membrane by using a different molecular building block. That way we can adapt it to suit any need."
Schneider explained their methodology "When making a membrane, a lot of researchers start out with graphene, which is very thin, but not porous. They then try to punch holes in it to make it more permeable. We’ve done the reverse by assembling small molecules and building a larger porous membrane from those molecules. Compared to graphene, it contains imperfections, but that’s what gives it its special properties."
He concluded "Much of the research in this field was focused on creating better catalysts, membranes were somewhat of a dead end. This new discovery opens up whole new possibilities for power generation, desalination and for building much more efficient fuel cells."