Graphene Solar Cell Generates Electricity From Sun And Rain
The energy from the sun is one of the most renewable and cleanest sources of thermal and electrical energy all over the world, but experts believe there are still a lot of untapped potential when it comes to the efficiency of solar cells.
And while solar energy is on the rise, one of its disadvantages is that photovoltaic cells no longer produce energy during inclement weather.
The question now is this: could we generate electricity from the rain, too?
Apparently, we can. A group of scientists in China have developed a new method for making an "all-weather" solar cell that is essentially triggered by both light from the sun and raindrops.
How so? The key ingredient is the "miracle" material: graphene.
Come Rain, Come Shine
Graphene is an impressive material because of its conductivity, allowing electrons to freely flow across the surface.
When the material is placed in an aqueous solution, it can bind positively-charged ions with negatively-charged electrons. Experts take advantage of this property to take away organic dyes and lead ions from solutions.
Now, researchers from the Ocean University of China plan to use sheets of graphene to divide the positively-charged ions in raindrops - which include calcium, ammonium and sodium - that can bind to the surface, and thus generate electricity.
Raindrops are not made up of pure water. These droplets contain salts that split up into negative and positive ions. Because of this, the research team led by Professor Qunwei Tang believes power can be generated through this simple chemical reaction.
During initial tests, scientists used slightly salty water to mimic rain. So far, the tests yielded promising results: the team was able to trigger hundreds of microvolts. The material also efficiently converted solar energy to light energy at 6.35 percent.
Tang and his colleagues used a cheap, thin-film solar cell called a "dye-sensitized" solar cell and added a layer of graphene to it. It was then put on a visible backing of indium tin oxide and plastic.
This resulted in the all-weather solar cell that could produce power from sunlight and rain.
Implications Of The Technology
The incredible experiment is still in its proof-of-concept phase, so further work needs to be done before it can undergo large-scale production.
Nevertheless, Ocean University scientists hope their work can lay the foundations for future all-weather solar cells and add to the increasing influence of renewable energy globally.
Their work on graphene, published in the journal Angewandte Chemie, is not the first study to tap into the "powers" of the material. In October last year, experts from Birmingham University revealed that they have developed their own method of controlling the electronic properties of graphene at the nanolevel.
Photo: Lilly Andersen | Flickr