In the future, energy production via photosynthesis might not just be for plants. 

A Purdue University research group wants to add artificial photosynthesis to the roster of renewable energy technologies. The lead researcher says this energy production method could overcome some of the environmental and logistical barriers that accompany other technologies such as wind and solar.

Photovoltaic technology is the closest thing to artificial photosynthesis currently available. But solar cells are inefficient, usually capturing only about 20% of the sun’s energy. Plus, they require large batteries to store energy that is not immediately used. Purdue professor Yulia Pushkar said that artificial photosynthesis innovations could overcome both of those obstacles.

“With artificial photosynthesis, there are not fundamental physical limitations,” she said in a news release. “You can very easily imagine a system that is 60% efficient because we already have a precedent in natural photosynthesis. And if we get very ambitious, we could even envision a system of up to 80% efficiency.”

The process

The research team is developing an artificial leaf that collects sunlight and splits water molecules to create hydrogen.

“Photosynthesis is massively efficient when it comes to splitting water, a first step of artificial photosynthesis,” Pushkar said. “Photosystems II proteins in plants do this a thousand times a second. Blink, and it’s done.” 

The hydrogen itself can be used as a fuel or added to other fuels such as natural gas. The hydrogen could be incorporated into fuel cells that power a variety of things, such as electric vehicles, homes, and commercial buildings.

The Purdue researchers prioritize using materials that are nontoxic, abundant across the world, and easily accessible. They experiment with natural proteins and synthetic catalysts to figure out what works best for the process and why.

Inherent challenge

Scientists have been working for decades on perfecting artificial photosynthesis — including recent research at the University of Michigan and Argonne National Laboratory. 

But photosynthesis is a complex natural process that plants perfected over billions of years. Figuring out an optimal artificial equivalent takes time. 

The process is multifaceted and the scientific reactions are quite complex. Specifically, the process of splitting water to make hydrogen is challenging and intricate. Pushkar’s most recent discovery on artificial photosynthesis provided insight into how the water molecules split during photosynthesis.

Pushkar predicts that enough progress will be made on artificial photosynthesis over the next 10 to 15 years that commercial technologies will then begin to emerge.