Light Cleanup

The sun is one of our primary sources of energy (unless you’re a cat—then, the point of a ray of sunshine is to sleep in it). Sunshine makes plants grow, keeps us from freezing to death, and can power our homes and workplaces.

You already know about photosynthesis, the process of plants using light to make energy. But have you ever heard of photocatalysis? Whoa—technical word alert! Let’s break that down.

Photo = light. Catalysis = making a chemical reaction work faster by using a catalyst (the thing that speeds up the reaction). In other words, photocatalysis is the use of light energy to make a chemical reaction work faster.

OK, so now you understand what photocatalysis IS, but what can it DO? Some pretty important stuff, as it turns out. Photocatalysis has been used for a while in air purifiers via ultraviolet light and titanium dioxide.

In 2018, a team of scientists led by Kyriakos Stylianou at the Laboratory of Molecular Simulation in Switzerland has discovered a way to use photocatalysis to clean water, as well. They’ve developed a system that can perform two types of photocatalysis at the same time. The first reaction splits water into its two components, hydrogen and oxygen (bonus: the hydrogen can be used for fuel cells in things like satellites and space shuttles). The second reaction cleans organic pollutants out of the water.

There you go: a photocatalytic two-fer. Cleaner water and cleaner energy.