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Graphene-Coated Solar Panels Could Someday Convert Raindrops Into Electricity

ByAllison EckNOVA NextNOVA Next

Graphene is quickly becoming science’s new best friend.

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At just one atom thick, this sheet of carbon could both simplify and revolutionize technology—from tissue engineering to drug delivery . And when combined with salt water, it has unexpected potential.

Back in 2014,

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researchers in China discovered that exposing a graphene surface to salt water (in that particular case, copper chloride) generates an electric potential. Now, a team of scientists led by Qunwei Tang of China’s Ocean University has found that this effect could render solar panels more effective—even in the absence of sunlight.

No sun doesn't mean no use.

Here’s Olivia Goldhill, writing for Quartz:

Here’s how their planned solar panel would work. Raindrops would form a layer of positive ions, which are found in the salt of rainwater. Meanwhile, graphene is rich with delocalized electrons—which are free to move around. This forms a double layer—where positive and negative charges are separated—creating an electric potential between them. The separation in the double layer creates a voltage, just like in a battery.

Unfortunately, the test panel—which was already painted with water far saltier than typical rainwater—produced a small percentage of an average AA battery voltage. Another obstacle facing the team is the fact that graphene cannot yet be mass-produced (though, that could change ). Still, if the team can make improvements on their prototype, solar panels could someday become a lot more practical and widespread.

Photo credit: Dept of Energy Solar Decathlon / Flickr (CC BY-NC-ND 2.0)

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