Researchers from Israel have achieved record efficiency in converting solar energy into fuel. Now they want to incorporate a mechanism similar to photosynthesis into the process to achieve even better results.
A group of scientists from the Israel Institute of Technology has developed a photocatalyst that can split water into hydrogen fuel. They said that they used rod-shaped nanoparticles, which, with the help of light, generated positive and negative electrical charges. In the process, water molecules break down: negative charges produce hydrogen, and positive charges produce oxygen. In this case, reactions involving positive and negative charges must occur simultaneously.
If the positive and negative charges that are attracted to each other manage to recombine, they cancel each other out and energy is lost. So to make sure the charges were far enough apart, the team created unique heterostructures made up of a combination of different semiconductors. Using a model system, they separately studied the reduction and oxidation reactions and modified the heterostructure to optimize fuel production.
“We ended up with a photocatalytic system that uses sunlight to control chemical reactions. Such models will go a long way towards preserving the environment”.
from the text of researchers at the Israel Institute of Technology
The same team in 2016 presented a heterostructure where a stone selenide particle attracted positive charges, while negative charges accumulated at the tip. By adjusting the size of the quantum dot and the length of the rod, as well as other parameters, the researchers achieved one hundred percent conversion of sunlight into hydrogen. One nanoparticle of the photocatalyst produced about 360 thousand hydrogen molecules per hour.
Previously, scientists discovered that there was less phytoplankton in the oceans than scientists expected. This means that its role in the absorption of carbon dioxide by the oceans is lower than anticipated – and global warming may be faster than predicted. This became known from a study by scientists from NASA, published in the International Society for Microbial Ecology Journal.