Photosynthesis: Not Just for Plants?

You might already know the basics of how photosynthesis works. Plants use sunlight to make the food they need to live. But one day we might be able to use photosynthesis to run our cars, heat our homes, and more! Scientists are working on it right now!

Plants are like machines that turn light into food. They do it with a chemical called chlorophyll. Chlorophyll helps plants use the sun’s energy to split water into hydrogen and oxygen molecules. Plants turn hydrogen into food, but if we can figure out how to use the sun to split water, we could use hydrogen as fuel.

Scientists can already split water into hydrogen with a machine called an electrolyzer. But today’s electrolyzers run on electricity. That electricity has to be made somewhere. If it’s made in a power plant that uses fossil fuels, it can cause pollution and release the greenhouse gasses that cause climate change. Using the sun instead of electricity to create hydrogen — the way plants do — could be a cleaner form of energy. It’s called artificial photosynthesis.

Yulia Pushkar is a scientist who’s working on artificial photosynthesis. She’s a physicist at Purdue University in West Lafayette, Indiana. Physicists are scientists who study matter and energy. “If we want to create artificial photosynthesis, we have to create a material which will absorb the light and split the water,” Dr. Pushkar says.

Luckily, Dr. Pushkar and her team have done just that. They have created materials that split water into hydrogen under light. “Already today in Indiana, we can make a lot of clean hydrogen,” Dr. Pushkar says.

That sounds great, but there’s a problem. “The best electrolyzers have iridium inside. Iridium is very rare. If you say, ‘let’s do this everywhere around the world,’ we don’t have enough iridium,” Dr. Pushkar explains.

Now she’s working on a different way to make hydrogen from sunlight by using iron and carbon. “We did a lot of research with precious metals, but now we are trying to do everything with iron,” Dr. Puskar says. Iron is one of the most abundant elements on Earth. That means there’s a lot of it. It’s much easier and cheaper to find than iridium. If iron can be used, one day artificial photosynthesis panels could spring up in rows wherever it’s sunny, like solar panels do today.

Of course, just being able to make hydrogen isn’t enough. We also need to be able to use it in our cars and homes. Some buses in California already run on hydrogen fuel cells, but most of today’s vehicles still use gasoline. We’re not yet ready to power buildings with hydrogen fuel. But if we can make and use hydrogen, we won’t run out of it. And it doesn’t release harmful greenhouse gasses.

Dr. Pushkar is hopeful about artificial photosynthesis. “We and other researchers around the world are working incredibly hard to try to come up with accessible energy,” she told Purdue University’s News. “Energy that is clean and sustainable…  Our artificial photosynthesis is the way forward.”