When it comes to making efficient fuel cells, it's all about the catalyst. A good catalyst will result in faster, more efficient chemical reactions and, thus, increased energy output. Today's fuel cells typically rely on platinum-based catalysts. But scientists at American University believe that spinach—considered a "superfood" because it is so packed with nutrients—would make an excellent renewable carbon-rich catalyst, based on their proof-of-principle experiments described in a recent paper published in the journal ACS Omega. Popeye would definitely approve.
Spinach has a surprisingly long history in science; the notion of exploiting its photosynthetic and electrochemical properties has been around for about 40 years now. Spinach is plentiful, cheap, easy to grow, and rich in iron and nitrogen. Many (many!) years ago, as a budding young science writer, I attended a conference talk by physicist Elias Greenbaum (then with Oak Ridge National Labs) about his spinach-related research. Specifically, he was interested in the protein-based "reaction centers" in spinach leaves that are the basic mechanism for photosynthesis—the chemical process by which plants convert carbon dioxide into oxygen and carbohydrates.
There are two types of reaction centers. One type, known as photosystem 1 (PS1), converts carbon dioxide into sugar; the other, photosystem 2 (PS2), splits water to produce oxygen. There is a great deal of scientific interest in PS1, which acts like a tiny photosensitive battery, absorbing energy from sunlight and emitting electrons with nearly 100-percent efficiency. PS1s are capable of generating a light-induced flow of electricity in fractions of a second.