Scientists have developed a water-splitting device, which is capable of generating two different types of energy from the current artificial light synthesis equipment, except for some limitations.
U.S. A research team of the Lawrence Berkeley National Laboratory of the Department of Energy and the Center for the Artificial Lighting Synthesis of the Department of Energy has developed a new device named Hybrid Photoelectrochemical and Voltaic (HPV) Cell, which converts sunlight and water into hydrogen fuel and electricity.
Water division is an artificial light synthesis technique where sunlight is used to generate hydrogen fuel from water. However, there is not a design designed for content with the right combination of the optical, electronic and chemical properties needed to work efficiently there first.
Most water-splitting tools are made up of a heap of light-absorbent material, where each layer absorbs the different wavelengths of the solar spectrum, in which the visible energetic wavelength of infrared light or the more energetic wavelength of ultraviolet light Are there.
Each layer creates an electric voltage when it absorbs light which combines in a voltage which is large enough to divide the water into oxygen and hydrogen fuel.
However, the possibility of high-performance is compromised in this configuration when they are part of the water-splitting device. In the stack, along with other materials, the silicon limiting the current range running through the device and the system can potentially produce at least current, resulting in less solar fuels.
Gideon Segov, a postdoctoral researcher in the Chemical Sciences Division and Berkeley Lab’s Chief Writer JCAP, said in a statement: “It’s always driving a car in the first gear.” “This is the energy that you can harvest, but since silicon is not working on its maximum power point, so excited electrons in silicon do not have to go anywhere, so before using them for useful work Lose their energy. ”
In water splitting devices, the front surface is generally dedicated to solar fuel production, the previous surface acts as an electrical outlet. In their new device, the researchers added an additional electrical contact on the back surface of the silicon component, producing a device with two contacts in the device.
The extra back outlet allows the current to be divided into two, so that a part of the current contributes to the solar fuel production and the second part can be extracted as an electric power.
“And for our surprise, it worked!” Segov said. “In science, you are never really sure that everything is going to work even if your computer simulation says that they will. But it also makes fun. Our experiments were very good to validate the predictions of our simulations. . ”
On the basis of their calculations, a conventional solar hydrogen generator comprising the combination of silicon and bismuth vanadat generates hydrogen on solar energy, which is for hydrogen efficiency of 6.8 percent.
HPV cells also harvest the remaining electrons that do not contribute to the fuel production, but are used to generate electrical power. As a result, overall solar energy conversion efficiency has increased significantly.
Researchers will now examine whether they can use the HPEV concept for other applications, including reducing carbon dioxide emissions.
Segev said, “This was indeed a group effort, where many people with so many experiences were able to contribute.” “One and a half years after working together on a very difficult process, it was great to see that our experiments come together at the end.”
The study was published in Nature Materials.