RED STICK – LSU researchers are exploring new ways to use our planet’s oldest source of energy, sunlight, to create true green energy on demand. You’ve heard of solar cells and solar panels before, but David Vinyard, an assistant professor in LSU’s Department of Biological Sciences, is studying another way to harness the power of the Sun: photosynthesis.
The general idea of photosynthesis – the ability of a plant to absorb sunlight and use that energy to make sugars, or biomass, from water and carbon dioxide – is well known. But the exact mechanisms are still being discovered. Vinyard follows the process atom by atom, electron by electron.
“It’s shocking how little we know about how nature converts light energy into chemical energy, given that it happens on such a massive scale,” Vinyard said. “If we can learn the chemical and physical mechanisms used by nature, we can give these blueprints to chemists and engineers to develop clean energy conversion devices. Essentially, an artificial leaf.
An artificial leaf could be an inexpensive and efficient solar fuel cell. It could use light energy to extract electrons and hydrogen atoms from water, which could then be recombined to create hydrogen gas, a green fuel. Today, about 95% of all hydrogen is produced from natural gas, a fossil fuel, while an artificial leaf could produce it on demand using only water and sunlight.
“As global and domestic energy markets become increasingly sensitive to managing the carbon associated with our traditional energy sources, Dr. Vinyard’s work has the potential to help Louisiana diversify its energy economy by helping to provide more options in the composition of our energy sources,” said Jason Lanclos, director of the State Energy Office at the Louisiana Department of Natural Resources.
Vinyard, who received a US Department of Energy Early Career Award in 2019 to study energy conversion, studies the minute chemical mechanics of photosynthesis, a process that has been happening for billions of years. Vinyard’s lab conducts what it calls “very basic research,” following the process atom by atom, electron by electron, to determine exactly how chemical bonds are broken and formed at every tiny step.
Another important part of the photosynthetic pathway for creating clean energy, Vinyard says, is that natural photosynthesis only uses materials that are abundant on Earth. Many catalytic systems developed by chemists and engineers still rely on rare elements like platinum, rhodium, and palladium, which are not only expensive, but also found only in certain places.
An artificial leaf used for clean energy production would have two parts, according to Vinyard. First, a catalyst would use light energy to remove electrons and hydrogen atoms from water, or H2O. Ideally, this process would use inexpensive materials.
“Nature can split water molecules using an abundance of calcium and manganese, and that’s remarkable,” the researcher said. In the second part, the released hydrogen atoms and electrons are recombined to generate hydrogen gas, H2, which can be used as fuel.
“If we can learn how natural photosynthesis splits water using sunlight, we could apply that knowledge to the development of inexpensive and efficient solar fuel cells,” Vinyard said. “In an emergency, fuel could be generated on demand using only water and sunlight. One day, hopefully soon, this kind of technology could help us move away from the widespread use of fossil fuels.