Artificial material that mimics photosynthesis

Researchers at Florida State University (FSU) has discovered an artificial material that mimics photosynthesis and has the potential to create a sustainable energy source.

Credit: mervin07

The new material efficiently captures sunlight and the energy can be used to break down water into oxygen (O2) and hydrogen (H2) — a process known as oxidation. This is also what happens during photosynthesis when a plant uses light to break down water and carbohydrates, which are the main energy sources for the plant.

The discovery, detailed in The Journal of Physical Chemistry, generates exciting new prospects for how this process could be used to forge new energy sources in a carbon neutral way. Potentially, hydrogen could be transported to other locations and burned as fuel.

“In theory, this should be a self-sustaining energy source,” said one of the researchers, Assistant Professor of Chemical Engineering Jose L. Mendoza-Cortes, FSU High-Performance Materials Institute (HPMI), a multidisciplinary research institute dedicated to the research and development of advanced materials and manufacturing technologies. “Perhaps in the future, you could put this material on your roof and it could turn rain water into energy with the help of the sun.”

But, unlike many other energy sources, this won’t have a negative effect on the environment.

“You won’t generate carbon dioxide or waste,” he said.

The challenge was designing something that didn’t rust from the process of breaking down water that also trapped the energy and was inexpensive to create. What was discovered in this process converted an indirect band gap material to a direct band gap one.

Light with photo energy can penetrate indirect band gap materials more easily without getting absorbed and used for other purposes. Silicon, for example, is the most commonly known indirect gap band material. But to make the material effective, silicon solar cells are typically stacked, making them hundreds of micrometers thick. If they were any thinner, light would simply pass through them.

Creating a single-layer material that can efficiently trap light is a much more desirable outcome because it is simpler and cheaper to manufacture.

“This is why the discovery of this direct band gap material is so exciting,” Mendoza-Cortes said. “It is cheap, it is efficient and you do not need a large amount to capture enough sunlight to carry out fuel generation.”

The research is supported by HPMI, the FSU Research Computing Center, the National High Magnetic Field Laboratory and the Lawrence Berkeley National Laboratory.

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