Artificial Photosynthesis Promises Clean, Sustainable Source of Energy

(Purdue University/SciTechDaily) ... The closest process to artificial photosynthesis humans have today is photovoltaic technology, where a solar cell converts the sun’s energy into electricity. That process is famously inefficient, able to capture only about 20% of the sun’s energy. Photosynthesis, on the other hand, is radically more efficient; it is capable of storing 60% of the sun’s energy as chemical energy in associated biomolecules.

The efficiency of simple photovoltaic cells – solar panels – is limited by semiconductors’ ability to absorb light energy and by the cell’s ability to produce power. That limit is something scientists could surpass with synthetic photosynthesis.

“With artificial photosynthesis, there are not fundamental physical limitations,” Pushkar (Yulia Puskhar, a biophysicist and professor of physics in Purdue’s College of Science) said. “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.

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

Pushkar’s group is mimicking the process by building her own artificial leaf analog that collects light and splits water molecules to generate hydrogen. Hydrogen can be used as a fuel by itself via fuel cells or be added to other fuels such as natural gas, or built into fuel cells to power everything from vehicles to houses to small electronic devices, laboratories and hospitals. Her most recent discovery, an insight into the way water molecules split during photosynthesis, was recently published in the journal Chem Catalysis: Cell Press.

Scientists in Pushkar’s lab experiment with natural photosystem II proteins and synthetic catalysts combinations in attempts to understand what works best – and why. She also puts a priority on using compounds and chemicals that are readily abundant on Earth, easily accessible and nontoxic to the planet. READ MORE

“Do multinuclear 3d metal catalysts achieve O–O bond formation via radical coupling or via water nucleophilic attack? WNA leads the way in [Co₄O₄]ⁿ⁺” by Roman Ezhov, Alireza Karbakhsh Ravari, Gabriel Bury, Paul F. Smith and Yulia Pushkar, 3 May 2021, Chem Catalysis: Cell Press. DOI: 10.1016/j.checat.2021.03.013